modification required due to the change of fused_all_reduce API
modification required due to the change of fused_all_reduce API

apache/incubator-singa,nudles/incubator-singa,apache/incubator-singa,nudles/incubator-singa,nudles/incubator-singa,apache/incubator-singa,nudles/incubator-singa,apache/incubator-singa,nudles/incubator-singa,apache/incubator-singa