pow is total overkill for x*x, introduce pow2 inline function to fix it.

fix a warning.

git-svn-id: https://dolphin-emu.googlecode.com/svn/trunk@2323 8ced0084-cf51-0410-be5f-012b33b47a6e

Source/Core/Common/Src/MathUtil.h

@@ -27,6 +27,9 @@
    uses round towards zero.
  */
 
+inline float pow2f(float x) {return x * x;}
+inline double pow2(double x) {return x * x;}
+
 void SaveSSEState();
 void LoadSSEState();
 void LoadDefaultSSEState();