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/Hexagon/HexagonHardwareLoops.cpp b/llvm/lib/Target/Hexagon/HexagonHardwareLoops.cpp
index d814fa7..715fd52 100644
--- a/llvm/lib/Target/Hexagon/HexagonHardwareLoops.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonHardwareLoops.cpp
@@ -377,7 +377,7 @@
 
 bool HexagonHardwareLoops::runOnMachineFunction(MachineFunction &MF) {
   DEBUG(dbgs() << "********* Hexagon Hardware Loops *********\n");
-  if (skipFunction(*MF.getFunction()))
+  if (skipFunction(MF.getFunction()))
     return false;
 
   bool Changed = false;