fix(compiler.cpp): only add ctrl edge in reduce struct when training (#1028)

oneflow/core/job/compiler.cpp

@@ -60,7 +60,7 @@ Plan Compiler::DoCompile() {
   task_gph->ForEachNode(std::bind(&TaskNode::EraseEmptyProducedRegst, _1));
   task_gph->ForEachNode(std::bind(&TaskNode::ClearOutOfDateConsumedRegst, _1));
   task_gph->AddOrderingCtrlEdgeInSameChain();
-  if (Global<JobDesc>::Get()->other_conf().use_ordered_allreduce_in_mdupdt()) {
+  if (job_desc->IsTrain() && job_desc->other_conf().use_ordered_allreduce_in_mdupdt()) {
     task_gph->AddCtrlEdgeInReduceStruct();
   }
   if (job_desc->IsTrain()) { task_gph->AddOrderCtrlEdgeBetweenCopyAndMdUpdt(); }