Add check_return flag

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c
index 0b243f4..985c9af 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -1878,6 +1878,7 @@
 
 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
 
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_tls13_parse_new_session_ticket_exts( mbedtls_ssl_context *ssl,
                                                     const unsigned char *buf,
                                                     const unsigned char *end )
@@ -1923,6 +1924,7 @@
  * } NewSessionTicket;
  *
  */
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_tls13_parse_new_session_ticket( mbedtls_ssl_context *ssl,
                                                unsigned char *buf,
                                                unsigned char *end,
@@ -2007,6 +2009,7 @@
     return( 0 );
 }
 
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_tls13_postprocess_new_session_ticket( mbedtls_ssl_context *ssl,
                                                      unsigned char *ticket_nonce,
                                                      size_t ticket_nonce_len )
@@ -2073,6 +2076,7 @@
 /*
  * Handler for MBEDTLS_SSL_NEW_SESSION_TICKET
  */
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_tls13_process_new_session_ticket( mbedtls_ssl_context *ssl )
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;