Remove dead code causing a warning.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52502 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Scalar/InstructionCombining.cpp

@@ -1655,8 +1655,6 @@ static Instruction *AssociativeOpt(BinaryOperator &Root, const Functor &F) {
     // If the functor wants to apply the optimization to the RHS of LHSI,
     // reassociate the expression from ((? op A) op B) to (? op (A op B))
     if (ShouldApply) {
-      BasicBlock *BB = Root.getParent();
-
       // Now all of the instructions are in the current basic block, go ahead
       // and perform the reassociation.
       Instruction *TmpLHSI = cast<Instruction>(Root.getOperand(0));