Make \retval commands non-empty

Pacify Clang >=15 which complained:
```
include/psa/crypto.h:91:23: error: empty paragraph passed to '\retval' command [-Werror,-Wdocumentation]
 * \retval #PSA_SUCCESS
   ~~~~~~~~~~~~~~~~~~~^
```

This commit performs the following systematic replacement:
```
perl -i -0777 -p -e 's/([\\@])(retval +\S+)\n(?! *\*? *([^\n \\*\/]|\\[cp]\b))/$1$2 ${1}emptydescription\n/g' $(git ls-files '*.[hc]' '*.function' '*.jinja')
```
i.e. add an `\emptydescription` argument to `\retval` commands (or
`@retval`, which we don't normally used) that are followed by a single word,
unless the next line looks like it contains text which would be the
description.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/include/psa/crypto_extra.h b/include/psa/crypto_extra.h
index bd1b5af..582d942 100644
--- a/include/psa/crypto_extra.h
+++ b/include/psa/crypto_extra.h
@@ -189,12 +189,12 @@
  *         or the specified slot number is not valid.
  * \retval #PSA_ERROR_NOT_PERMITTED
  *         The caller is not authorized to register the specified key slot.
- * \retval #PSA_ERROR_INSUFFICIENT_MEMORY
- * \retval #PSA_ERROR_INSUFFICIENT_STORAGE
- * \retval #PSA_ERROR_COMMUNICATION_FAILURE
- * \retval #PSA_ERROR_DATA_INVALID
- * \retval #PSA_ERROR_DATA_CORRUPT
- * \retval #PSA_ERROR_CORRUPTION_DETECTED
+ * \retval #PSA_ERROR_INSUFFICIENT_MEMORY \emptydescription
+ * \retval #PSA_ERROR_INSUFFICIENT_STORAGE \emptydescription
+ * \retval #PSA_ERROR_COMMUNICATION_FAILURE \emptydescription
+ * \retval #PSA_ERROR_DATA_INVALID \emptydescription
+ * \retval #PSA_ERROR_DATA_CORRUPT \emptydescription
+ * \retval #PSA_ERROR_CORRUPTION_DETECTED \emptydescription
  * \retval #PSA_ERROR_BAD_STATE
  *         The library has not been previously initialized by psa_crypto_init().
  *         It is implementation-dependent whether a failure to initialize
@@ -491,10 +491,10 @@
  *                              according to \p type as described above.
  * \param data_length           Size of the \p data buffer in bytes.
  *
- * \retval #PSA_SUCCESS
- * \retval #PSA_ERROR_INVALID_ARGUMENT
- * \retval #PSA_ERROR_NOT_SUPPORTED
- * \retval #PSA_ERROR_INSUFFICIENT_MEMORY
+ * \retval #PSA_SUCCESS \emptydescription
+ * \retval #PSA_ERROR_INVALID_ARGUMENT \emptydescription
+ * \retval #PSA_ERROR_NOT_SUPPORTED \emptydescription
+ * \retval #PSA_ERROR_INSUFFICIENT_MEMORY \emptydescription
  */
 psa_status_t psa_set_key_domain_parameters(psa_key_attributes_t *attributes,
                                            psa_key_type_t type,
@@ -521,8 +521,8 @@
  * \param[out] data_length      On success, the number of bytes
  *                              that make up the key domain parameters data.
  *
- * \retval #PSA_SUCCESS
- * \retval #PSA_ERROR_BUFFER_TOO_SMALL
+ * \retval #PSA_SUCCESS \emptydescription
+ * \retval #PSA_ERROR_BUFFER_TOO_SMALL \emptydescription
  */
 psa_status_t psa_get_key_domain_parameters(
     const psa_key_attributes_t *attributes,
@@ -1352,8 +1352,8 @@
  *         compatible with the PAKE algorithm, or the hash algorithm in
  *         \p cipher_suite is not supported or not compatible with the PAKE
  *         algorithm and primitive.
- * \retval #PSA_ERROR_COMMUNICATION_FAILURE
- * \retval #PSA_ERROR_CORRUPTION_DETECTED
+ * \retval #PSA_ERROR_COMMUNICATION_FAILURE \emptydescription
+ * \retval #PSA_ERROR_CORRUPTION_DETECTED \emptydescription
  * \retval #PSA_ERROR_BAD_STATE
  *         The operation state is not valid, or
  *         the library has not been previously initialized by psa_crypto_init().
@@ -1397,11 +1397,11 @@
  * \retval #PSA_ERROR_NOT_SUPPORTED
  *         The key type or key size of \p password is not supported with the
  *         \p operation's cipher suite.
- * \retval #PSA_ERROR_COMMUNICATION_FAILURE
- * \retval #PSA_ERROR_CORRUPTION_DETECTED
- * \retval #PSA_ERROR_STORAGE_FAILURE
- * \retval #PSA_ERROR_DATA_CORRUPT
- * \retval #PSA_ERROR_DATA_INVALID
+ * \retval #PSA_ERROR_COMMUNICATION_FAILURE \emptydescription
+ * \retval #PSA_ERROR_CORRUPTION_DETECTED \emptydescription
+ * \retval #PSA_ERROR_STORAGE_FAILURE \emptydescription
+ * \retval #PSA_ERROR_DATA_CORRUPT \emptydescription
+ * \retval #PSA_ERROR_DATA_INVALID \emptydescription
  * \retval #PSA_ERROR_BAD_STATE
  *         The operation state is not valid (it must have been set up.), or
  *         the library has not been previously initialized by psa_crypto_init().
@@ -1439,9 +1439,9 @@
  *         suite.
  * \retval #PSA_ERROR_NOT_SUPPORTED
  *         The value of \p user_id is not supported by the implementation.
- * \retval #PSA_ERROR_INSUFFICIENT_MEMORY
- * \retval #PSA_ERROR_COMMUNICATION_FAILURE
- * \retval #PSA_ERROR_CORRUPTION_DETECTED
+ * \retval #PSA_ERROR_INSUFFICIENT_MEMORY \emptydescription
+ * \retval #PSA_ERROR_COMMUNICATION_FAILURE \emptydescription
+ * \retval #PSA_ERROR_CORRUPTION_DETECTED \emptydescription
  * \retval #PSA_ERROR_BAD_STATE
  *         The operation state is not valid, or
  *         the library has not been previously initialized by psa_crypto_init().
@@ -1480,9 +1480,9 @@
  *         suite.
  * \retval #PSA_ERROR_NOT_SUPPORTED
  *         The algorithm doesn't associate a second identity with the session.
- * \retval #PSA_ERROR_INSUFFICIENT_MEMORY
- * \retval #PSA_ERROR_COMMUNICATION_FAILURE
- * \retval #PSA_ERROR_CORRUPTION_DETECTED
+ * \retval #PSA_ERROR_INSUFFICIENT_MEMORY \emptydescription
+ * \retval #PSA_ERROR_COMMUNICATION_FAILURE \emptydescription
+ * \retval #PSA_ERROR_CORRUPTION_DETECTED \emptydescription
  * \retval #PSA_ERROR_BAD_STATE
  *         Calling psa_pake_set_peer() is invalid with the \p operation's
  *         algorithm, the operation state is not valid, or the library has not
@@ -1524,8 +1524,8 @@
  *         The \p role is not a valid PAKE role in the \p operation’s algorithm.
  * \retval #PSA_ERROR_NOT_SUPPORTED
  *         The \p role for this algorithm is not supported or is not valid.
- * \retval #PSA_ERROR_COMMUNICATION_FAILURE
- * \retval #PSA_ERROR_CORRUPTION_DETECTED
+ * \retval #PSA_ERROR_COMMUNICATION_FAILURE \emptydescription
+ * \retval #PSA_ERROR_CORRUPTION_DETECTED \emptydescription
  * \retval #PSA_ERROR_BAD_STATE
  *         The operation state is not valid, or
  *         the library has not been previously initialized by psa_crypto_init().
@@ -1575,13 +1575,13 @@
  *         \p step is not compatible with the operation's algorithm.
  * \retval #PSA_ERROR_NOT_SUPPORTED
  *         \p step is not supported with the operation's algorithm.
- * \retval #PSA_ERROR_INSUFFICIENT_ENTROPY
- * \retval #PSA_ERROR_INSUFFICIENT_MEMORY
- * \retval #PSA_ERROR_COMMUNICATION_FAILURE
- * \retval #PSA_ERROR_CORRUPTION_DETECTED
- * \retval #PSA_ERROR_STORAGE_FAILURE
- * \retval #PSA_ERROR_DATA_CORRUPT
- * \retval #PSA_ERROR_DATA_INVALID
+ * \retval #PSA_ERROR_INSUFFICIENT_ENTROPY \emptydescription
+ * \retval #PSA_ERROR_INSUFFICIENT_MEMORY \emptydescription
+ * \retval #PSA_ERROR_COMMUNICATION_FAILURE \emptydescription
+ * \retval #PSA_ERROR_CORRUPTION_DETECTED \emptydescription
+ * \retval #PSA_ERROR_STORAGE_FAILURE \emptydescription
+ * \retval #PSA_ERROR_DATA_CORRUPT \emptydescription
+ * \retval #PSA_ERROR_DATA_INVALID \emptydescription
  * \retval #PSA_ERROR_BAD_STATE
  *         The operation state is not valid (it must be active, and fully set
  *         up, and this call must conform to the algorithm's requirements
@@ -1631,12 +1631,12 @@
  *         \p step p is not supported with the \p operation's algorithm, or the
  *         \p input is not supported for the \p operation's algorithm, cipher
  *         suite or \p step.
- * \retval #PSA_ERROR_INSUFFICIENT_MEMORY
- * \retval #PSA_ERROR_COMMUNICATION_FAILURE
- * \retval #PSA_ERROR_CORRUPTION_DETECTED
- * \retval #PSA_ERROR_STORAGE_FAILURE
- * \retval #PSA_ERROR_DATA_CORRUPT
- * \retval #PSA_ERROR_DATA_INVALID
+ * \retval #PSA_ERROR_INSUFFICIENT_MEMORY \emptydescription
+ * \retval #PSA_ERROR_COMMUNICATION_FAILURE \emptydescription
+ * \retval #PSA_ERROR_CORRUPTION_DETECTED \emptydescription
+ * \retval #PSA_ERROR_STORAGE_FAILURE \emptydescription
+ * \retval #PSA_ERROR_DATA_CORRUPT \emptydescription
+ * \retval #PSA_ERROR_DATA_INVALID \emptydescription
  * \retval #PSA_ERROR_BAD_STATE
  *         The operation state is not valid (it must be active, and fully set
  *         up, and this call must conform to the algorithm's requirements
@@ -1691,12 +1691,12 @@
  * \retval #PSA_ERROR_NOT_SUPPORTED
  *         Input from a PAKE is not supported by the algorithm in the \p output
  *         key derivation operation.
- * \retval #PSA_ERROR_INSUFFICIENT_MEMORY
- * \retval #PSA_ERROR_COMMUNICATION_FAILURE
- * \retval #PSA_ERROR_CORRUPTION_DETECTED
- * \retval #PSA_ERROR_STORAGE_FAILURE
- * \retval #PSA_ERROR_DATA_CORRUPT
- * \retval #PSA_ERROR_DATA_INVALID
+ * \retval #PSA_ERROR_INSUFFICIENT_MEMORY \emptydescription
+ * \retval #PSA_ERROR_COMMUNICATION_FAILURE \emptydescription
+ * \retval #PSA_ERROR_CORRUPTION_DETECTED \emptydescription
+ * \retval #PSA_ERROR_STORAGE_FAILURE \emptydescription
+ * \retval #PSA_ERROR_DATA_CORRUPT \emptydescription
+ * \retval #PSA_ERROR_DATA_INVALID \emptydescription
  * \retval #PSA_ERROR_BAD_STATE
  *         The PAKE operation state is not valid (it must be active, but beyond
  *         that validity is specific to the algorithm), or
@@ -1728,8 +1728,8 @@
  *
  * \retval #PSA_SUCCESS
  *         Success.
- * \retval #PSA_ERROR_COMMUNICATION_FAILURE
- * \retval #PSA_ERROR_CORRUPTION_DETECTED
+ * \retval #PSA_ERROR_COMMUNICATION_FAILURE \emptydescription
+ * \retval #PSA_ERROR_CORRUPTION_DETECTED \emptydescription
  * \retval #PSA_ERROR_BAD_STATE
  *         The library has not been previously initialized by psa_crypto_init().
  *         It is implementation-dependent whether a failure to initialize