Fix a Wunused-lambda-capture warning.

The capture was added in the first commit of https://reviews.llvm.org/D61934
when it was used. In the reland, the use was removed but the capture
wasn't removed.

llvm-svn: 363155

llvm/lib/Analysis/ScalarEvolutionExpander.cpp

@@ -783,7 +783,7 @@ Value *SCEVExpander::visitMulExpr(const SCEVMulExpr *S) {
   // Expand the calculation of X pow N in the following manner:
   // Let N = P1 + P2 + ... + PK, where all P are powers of 2. Then:
   // X pow N = (X pow P1) * (X pow P2) * ... * (X pow PK).
-  const auto ExpandOpBinPowN = [this, &I, &OpsAndLoops, &Ty, &S]() {
+  const auto ExpandOpBinPowN = [this, &I, &OpsAndLoops, &Ty]() {
     auto E = I;
     // Calculate how many times the same operand from the same loop is included
     // into this power.