[CodeGen] Fix inconsistent declaration parameter name

llvm-svn: 337200
diff --git a/llvm/lib/CodeGen/OptimizePHIs.cpp b/llvm/lib/CodeGen/OptimizePHIs.cpp
index 8972867..befa842 100644
--- a/llvm/lib/CodeGen/OptimizePHIs.cpp
+++ b/llvm/lib/CodeGen/OptimizePHIs.cpp
@@ -45,7 +45,7 @@
       initializeOptimizePHIsPass(*PassRegistry::getPassRegistry());
     }
 
-    bool runOnMachineFunction(MachineFunction &MF) override;
+    bool runOnMachineFunction(MachineFunction &Fn) override;
 
     void getAnalysisUsage(AnalysisUsage &AU) const override {
       AU.setPreservesCFG();