Silence some compiler warnings.

llvm-svn: 51115
diff --git a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
index 9c61ed8..f0d9f36 100644
--- a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
@@ -1317,6 +1317,7 @@
     void remove(SUnit *SU) {
       assert(!Queue.empty() && "Queue is empty!");
       size_t RemovedNum = Queue.erase(SU);
+      RemovedNum; // Silence compiler warning.
       assert(RemovedNum > 0 && "Not in queue!");
       assert(RemovedNum == 1 && "Multiple times in the queue!");
       SU->NodeQueueId = 0;