tests: net: socket: Add missing return code check

Add missing check.

Signed-off-by: Andrei Emeltchenko <[email protected]>

Author: finikorg

tests/net/socket/offload_dispatcher/src/main.c

@@ -815,6 +815,7 @@ static void test_tls_native_iface_native(void)
 
 	ret = zsock_setsockopt(test_sock, SOL_TLS, TLS_NATIVE,
 			       &tls_native, sizeof(tls_native));
+	zassert_equal(0, ret, "setsockopt() failed");
 	zassert_false(test_socket_ctx[OFFLOAD_1].socket_called,
 		     "TLS socket dispatched to wrong iface");
 	zassert_false(test_socket_ctx[OFFLOAD_2].socket_called,