Follow up of "div/rem on x86 and x86_64", to tidy up the code a little.

Change-Id: Ibf39cbc8ac1d773599d70be2cb1e941674b60f1d
diff --git a/compiler/optimizing/code_generator_x86.h b/compiler/optimizing/code_generator_x86.h
index a78f564..a5489d2 100644
--- a/compiler/optimizing/code_generator_x86.h
+++ b/compiler/optimizing/code_generator_x86.h
@@ -164,7 +164,7 @@
   void HandleBitwiseOperation(HBinaryOperation* instruction);
   void GenerateDivRemIntegral(HBinaryOperation* instruction);
   void DivRemOneOrMinusOne(HBinaryOperation* instruction);
-  void DivByPowerOfTwo(HBinaryOperation* instruction);
+  void DivByPowerOfTwo(HDiv* instruction);
   void GenerateDivRemWithAnyConstant(HBinaryOperation* instruction);
   void GenerateRemFP(HRem *rem);
   void HandleShift(HBinaryOperation* instruction);