mark all local functions as static

Source/Core/VideoCommon/VertexShaderManager.cpp

@@ -53,7 +53,7 @@ static ProjectionHack g_ProjHack1;
 static ProjectionHack g_ProjHack2;
 } // Namespace
 
-float PHackValue(std::string sValue)
+static float PHackValue(std::string sValue)
 {
 	float f = 0;
 	bool fp = false;