[InstCombine] visitFCmpInst - appease copy+paste pattern warning. NFCI.

PVS Studio's copy+paste recognizer was seeing this as a typo, technically Op0/Op1 in a fcmp should always be the same type, but we might as well avoid the issue.

Reported in https://www.viva64.com/en/b/0629/

llvm-svn: 359482

llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp

@@ -5512,7 +5512,7 @@ Instruction *InstCombiner::visitFCmpInst(FCmpInst &I) {
       return &I;
     }
     if (!match(Op1, m_PosZeroFP()) && isKnownNeverNaN(Op1, &TLI)) {
-      I.setOperand(1, ConstantFP::getNullValue(Op0->getType()));
+      I.setOperand(1, ConstantFP::getNullValue(Op1->getType()));
       return &I;
     }
   }