Add missing asterisk to doxygen closures

Clarify section names next to closing braces
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
diff --git a/include/mbedtls/x509.h b/include/mbedtls/x509.h
index 9a4be95..22d0a2c 100644
--- a/include/mbedtls/x509.h
+++ b/include/mbedtls/x509.h
@@ -93,7 +93,7 @@
 #define MBEDTLS_ERR_X509_BUFFER_TOO_SMALL                 -0x2980
 /** A fatal error occurred, eg the chain is too long or the vrfy callback failed. */
 #define MBEDTLS_ERR_X509_FATAL_ERROR                      -0x3000
-/* \} name */
+/** \} name X509 Error codes */
 
 /**
  * \name X509 Verify codes
@@ -121,8 +121,8 @@
 #define MBEDTLS_X509_BADCRL_BAD_PK           0x040000  /**< The CRL is signed with an unacceptable PK alg (eg RSA vs ECDSA). */
 #define MBEDTLS_X509_BADCRL_BAD_KEY          0x080000  /**< The CRL is signed with an unacceptable key (eg bad curve, RSA too short). */
 
-/* \} name */
-/* \} addtogroup x509_module */
+/** \} name X509 Verify codes */
+/** \} addtogroup x509_module */
 
 /*
  * X.509 v3 Subject Alternative Name types.