doxygen: fix parameter name typos and misused \p commands

\p is reserved for function parameters.
\c is used to describe other values and variables.
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
diff --git a/include/mbedtls/ecdsa.h b/include/mbedtls/ecdsa.h
index e797c1a..7e8a8c1 100644
--- a/include/mbedtls/ecdsa.h
+++ b/include/mbedtls/ecdsa.h
@@ -207,8 +207,9 @@
  * \param md_alg        The hash algorithm used to hash the original data.
  * \param f_rng_blind   The RNG function used for blinding. This must not be
  *                      \c NULL.
- * \param p_rng_blind   The RNG context to be passed to \p f_rng. This may be
- *                      \c NULL if \p f_rng doesn't need a context parameter.
+ * \param p_rng_blind   The RNG context to be passed to \p f_rng_blind. This
+ *                      may be \c NULL if \p f_rng_blind doesn't need a context
+ *                      parameter.
  *
  * \return          \c 0 on success.
  * \return          An \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_MPI_XXX
@@ -459,7 +460,7 @@
  *                  via mbedtls_ecdsa_genkey() or mbedtls_ecdsa_from_keypair().
  * \param md_alg    The message digest that was used to hash the message.
  * \param hash      The message hash to be signed. This must be a readable
- *                  buffer of length \p blen Bytes.
+ *                  buffer of length \p hlen Bytes.
  * \param hlen      The length of the hash \p hash in Bytes.
  * \param sig       The buffer to which to write the signature. This must be a
  *                  writable buffer of length at least twice as large as the
@@ -502,7 +503,7 @@
  *                  via mbedtls_ecdsa_genkey() or mbedtls_ecdsa_from_keypair().
  * \param md_alg    The message digest that was used to hash the message.
  * \param hash      The message hash to be signed. This must be a readable
- *                  buffer of length \p blen Bytes.
+ *                  buffer of length \p hlen Bytes.
  * \param hlen      The length of the hash \p hash in Bytes.
  * \param sig       The buffer to which to write the signature. This must be a
  *                  writable buffer of length at least twice as large as the
@@ -549,7 +550,7 @@
  * \param ctx       The ECDSA context to use. This must be initialized
  *                  and have a group and public key bound to it.
  * \param hash      The message hash that was signed. This must be a readable
- *                  buffer of length \p size Bytes.
+ *                  buffer of length \p hlen Bytes.
  * \param hlen      The size of the hash \p hash.
  * \param sig       The signature to read and verify. This must be a readable
  *                  buffer of length \p slen Bytes.
@@ -579,7 +580,7 @@
  * \param ctx       The ECDSA context to use. This must be initialized
  *                  and have a group and public key bound to it.
  * \param hash      The message hash that was signed. This must be a readable
- *                  buffer of length \p size Bytes.
+ *                  buffer of length \p hlen Bytes.
  * \param hlen      The size of the hash \p hash.
  * \param sig       The signature to read and verify. This must be a readable
  *                  buffer of length \p slen Bytes.