grammar tweak in comment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107321 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
index ebc76e9..2d08310 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
@@ -507,7 +507,7 @@
 }
 
 // ProcessSourceNode - Process nodes with source order numbers. These are added
-// to a vector which EmitSchedule use to determine how to insert dbg_value
+// to a vector which EmitSchedule uses to determine how to insert dbg_value
 // instructions in the right order.
 static void ProcessSourceNode(SDNode *N, SelectionDAG *DAG,
                            InstrEmitter &Emitter,