tests: fix leak in test-string-input-visitor

Free the list returned by visit_type_intList().

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

tests/test-string-input-visitor.c

@@ -228,6 +228,7 @@ static void test_visitor_in_fuzz(TestInputVisitorData *data,
 
         v = visitor_input_test_init(data, buf);
         visit_type_intList(v, NULL, &ilres, NULL);
+        qapi_free_intList(ilres);
         visitor_input_teardown(data, NULL);
 
         v = visitor_input_test_init(data, buf);