[LoopDist] Fix copy/paste mistake that said vectorize instead of distribute. NFC

Remove mention of sharing with new and old PM. The old PM code is gone.

Author: topperc

llvm/lib/Transforms/Scalar/LoopDistribute.cpp

@@ -965,11 +965,10 @@ class LoopDistributeForLoop {
 
 } // end anonymous namespace
 
-/// Shared implementation between new and old PMs.
 static bool runImpl(Function &F, LoopInfo *LI, DominatorTree *DT,
                     ScalarEvolution *SE, OptimizationRemarkEmitter *ORE,
                     LoopAccessInfoManager &LAIs) {
-  // Build up a worklist of inner-loops to vectorize. This is necessary as the
+  // Build up a worklist of inner-loops to distribute. This is necessary as the
   // act of distributing a loop creates new loops and can invalidate iterators
   // across the loops.
   SmallVector<Loop *, 8> Worklist;