DAG: Remove leftover debugging assert

Accidentally added in b540162

Author: arsenm

llvm/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp

@@ -718,11 +718,6 @@ SDValue DAGTypeLegalizer::SoftenFloatRes_ExpOp(SDNode *N) {
                              : RTLIB::getLDEXP(N->getValueType(0));
   assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unexpected fpowi.");
   if (!TLI.getLibcallName(LC)) {
-#ifndef NDEBUG
-    RTLIB::Libcall NewLC = RTLIB::getPOW(N->getValueType(0));
-    assert(NewLC != RTLIB::UNKNOWN_LIBCALL && "Unexpected fpow type");
-#endif
-
     // Some targets don't have a powi libcall; use pow instead.
     // FIXME: Implement this if some target needs it.
     DAG.getContext()->emitError("do not know how to soften fpowi to fpow");