DX9: Disable an annoying warning in vertex shader generator to clean …

…up our reports

warning X3571: pow(f, e) will not work for negative f, use abs(f) or conditionally handle negative values if you expect them

GPU/Directx9/VertexShaderGeneratorDX9.cpp

@@ -158,6 +158,7 @@ void GenerateVertexShaderDX9(int prim, char *buffer, bool useHWTransform) {
 		}
 	}
 
+	WRITE(p, "#pragma warning( disable : 3571 )\n");
 
 	if (gstate.isModeThrough())	{
 		WRITE(p, "float4x4 u_proj_through;\n");