Add certificteVerify

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 f1483c7..db9b762 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -1960,8 +1960,7 @@
  */
 static int ssl_tls13_write_client_certificate_verify( mbedtls_ssl_context *ssl )
 {
-    mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_CLIENT_FINISHED );
-    return( 0 );
+    return( mbedtls_ssl_tls13_write_certificate_verify( ssl ) );
 }
 
 /*