comment typo

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189635 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/MachineScheduler.cpp

@@ -649,7 +649,7 @@ void ScheduleDAGMI::findRootsAndBiasEdges(SmallVectorImpl<SUnit*> &TopRoots,
 /// available for use in the scheduler.
 ///
 /// The cyclic path estimation identifies a def-use pair that crosses the back
-/// end and considers the depth and height of the nodes. For example, consider
+/// edge and considers the depth and height of the nodes. For example, consider
 /// the following instruction sequence where each instruction has unit latency
 /// and defines an epomymous virtual register:
 ///