MachineFunction: Return reference for getFrameInfo(); NFC

getFrameInfo() never returns nullptr so we should use a reference
instead of a pointer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277017 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/StackMapLivenessAnalysis.cpp

@@ -113,7 +113,7 @@ bool StackMapLiveness::runOnMachineFunction(MachineFunction &MF) {
   ++NumStackMapFuncVisited;
 
   // Skip this function if there are no patchpoints to process.
-  if (!MF.getFrameInfo()->hasPatchPoint()) {
+  if (!MF.getFrameInfo().hasPatchPoint()) {
     ++NumStackMapFuncSkipped;
     return false;
   }