Update SAN parsing documentation
1) Fix typo in `mbedtls_x509_parse_subject_alt_name()` documentation.
2) Add a not in `mbedtls_x509_parse_subject_alt_name()` documentation,
stating that the lifetime of the target structure is restricted
by the lifetime ofthe parsed certificate.
@@ -410,11 +410,15 @@ int mbedtls_x509_crt_parse_path( mbedtls_x509_crt *chain, const char *path );
* as defined in RFC 4180 is supported.
*
* \note This function should be called on a single raw data of
- * subject alternative name. For example, after successfult
+ * subject alternative name. For example, after successful
* certificate parsing, one must iterate on every item in the
* \p crt->subject_alt_names sequence, and send it as parameter
* to this function.
*
+ * \note The target structure contains pointers to the raw data of the
+ * parsed certificate, and its lifetime is restricted by the
+ * lifetime of the certificate.
+ *
* \return \c 0 on success
* \return #MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE for an unsupported
* SAN type
