fix a bug I introduced in simplifycfg handling single entry phi

nodes. FoldSingleEntryPHINodes deletes the PHI, so there is no
need to delete it afterward.

llvm-svn: 60653

llvm/lib/Transforms/Utils/SimplifyCFG.cpp

@@ -1102,7 +1102,6 @@ static bool FoldCondBranchOnPHI(BranchInst *BI) {
   // Degenerate case of a single entry PHI.
   if (PN->getNumIncomingValues() == 1) {
     FoldSingleEntryPHINodes(PN->getParent());
-    PN->eraseFromParent();
     return true;    
   }