Address review feedback

Signed-off-by: Hanno Becker <hanno.becker@arm.com>
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index e8ca5e1..eb3dcc2 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -1907,8 +1907,8 @@
             MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) );
             mbedtls_ssl_send_alert_message( ssl,
                             MBEDTLS_SSL_ALERT_LEVEL_FATAL,
-                            MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
-            return( MBEDTLS_ERR_SSL_DECODE_ERROR );
+                            MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
+            return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
         }
 
         /* Read length of the next CRT in the chain. */