Fix copypasta in the async callback documentation
diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index b199e2e..b7dc98b 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -568,9 +568,8 @@
* does not wait for the operation to complete. This allows
* the handshake step to be non-blocking.
*
- * The parameters \p ssl and \p cert are
- * guaranteed to remain valid as long as the SSL
- * configuration remains valid. On the other hand, this
+ * The parameters \p ssl and \p cert are guaranteed to remain
+ * valid throughout the handshake. On the other hand, this
* function must save the contents of \p hash if the value
* is needed for later processing, because the \p hash buffer
* is no longer valid after this function returns.
@@ -588,7 +587,7 @@
* encoding, treating \p hash as the DigestInfo to be
* padded. In other words, apply EMSA-PKCS1-v1_5 starting
* from step 3, with `T = hash` and `tLen = hash_len`.
- * - If \p md_alg is #MBEDTLS_MD_NONE, apply the PKCS#1 v1.5
+ * - If `md_alg != MBEDTLS_MD_NONE`, apply the PKCS#1 v1.5
* encoding, treating \p hash as the hash to be encoded and
* padded. In other words, apply EMSA-PKCS1-v1_5 starting
* from step 2, with `digestAlgorithm` obtained by calling
@@ -645,9 +644,8 @@
* does not wait for the operation to complete. This allows
* the handshake step to be non-blocking.
*
- * The parameters \p ssl and \p cert are
- * guaranteed to remain valid as long as the SSL
- * configuration remains valid. On the other hand, this
+ * The parameters \p ssl and \p cert are guaranteed to remain
+ * valid throughout the handshake. On the other hand, this
* function must save the contents of \p input if the value
* is needed for later processing, because the \p input buffer
* is no longer valid after this function returns.