[CodeGen] Fix inconsistent declaration parameter name

llvm-svn: 337200
diff --git a/llvm/lib/CodeGen/SplitKit.h b/llvm/lib/CodeGen/SplitKit.h
index 2dafaf5..ed664e4 100644
--- a/llvm/lib/CodeGen/SplitKit.h
+++ b/llvm/lib/CodeGen/SplitKit.h
@@ -421,7 +421,7 @@
 
   SlotIndex buildSingleSubRegCopy(unsigned FromReg, unsigned ToReg,
       MachineBasicBlock &MB, MachineBasicBlock::iterator InsertBefore,
-      unsigned SubIdx, LiveInterval &DestLI, bool Late, SlotIndex PrevCopy);
+      unsigned SubIdx, LiveInterval &DestLI, bool Late, SlotIndex Def);
 
 public:
   /// Create a new SplitEditor for editing the LiveInterval analyzed by SA.