fix unused variable issue

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/library/ssl_tls13_generic.c b/library/ssl_tls13_generic.c
index a488faf..f0b84de 100644
--- a/library/ssl_tls13_generic.c
+++ b/library/ssl_tls13_generic.c
@@ -873,7 +873,7 @@
         }
         if( mbedtls_ssl_sig_alg_is_supported( ssl, *sig_alg) &&
             mbedtls_ssl_tls13_check_sig_alg_cert_key_match(
-                                              ssl, *sig_alg, own_key ) )
+                                                        *sig_alg, own_key ) )
         {
             *algorithm = *sig_alg;
             return( 0 );