MachineFunction: Return reference from getFunction(); NFC

The Function can never be nullptr so we can return a reference.

llvm-svn: 320884
diff --git a/llvm/lib/Target/Mips/MipsSEInstrInfo.cpp b/llvm/lib/Target/Mips/MipsSEInstrInfo.cpp
index 798d866..59b7679 100644
--- a/llvm/lib/Target/Mips/MipsSEInstrInfo.cpp
+++ b/llvm/lib/Target/Mips/MipsSEInstrInfo.cpp
@@ -231,8 +231,8 @@
 
   // Hi, Lo are normally caller save but they are callee save
   // for interrupt handling.
-  const Function *Func = MBB.getParent()->getFunction();
-  if (Func->hasFnAttribute("interrupt")) {
+  const Function &Func = MBB.getParent()->getFunction();
+  if (Func.hasFnAttribute("interrupt")) {
     if (Mips::HI32RegClass.hasSubClassEq(RC)) {
       BuildMI(MBB, I, DL, get(Mips::MFHI), Mips::K0);
       SrcReg = Mips::K0;
@@ -262,8 +262,8 @@
   MachineMemOperand *MMO = GetMemOperand(MBB, FI, MachineMemOperand::MOLoad);
   unsigned Opc = 0;
 
-  const Function *Func = MBB.getParent()->getFunction();
-  bool ReqIndirectLoad = Func->hasFnAttribute("interrupt") &&
+  const Function &Func = MBB.getParent()->getFunction();
+  bool ReqIndirectLoad = Func.hasFnAttribute("interrupt") &&
                          (DestReg == Mips::LO0 || DestReg == Mips::LO0_64 ||
                           DestReg == Mips::HI0 || DestReg == Mips::HI0_64);