modules/kmemcached: fixed broken api

modules/kmemcached/kmemcached.c

@@ -45,8 +45,7 @@ int kmemcached_deinit(struct kr_module *module)
 	struct engine *engine = module->data;
 	/* It was currently loaded, close cache */
 	if (kr_cache_storage == namedb_memcached_api) {
-		kr_cache_close(engine->resolver.cache);
-		engine->resolver.cache = NULL;
+		kr_cache_close(&engine->resolver.cache);
 	}
 	/* Prevent from loading it again */
 	for (unsigned i = 0; i < engine->storage_registry.len; ++i) {