Replace all include guard ifdefs with "#pragma once"

Source/Core/DolphinWX/GLInterface/X11_Util.h

@@ -1,21 +1,8 @@
-// Copyright (C) 2003 Dolphin Project.
+// Copyright 2013 Dolphin Emulator Project
+// Licensed under GPLv2
+// Refer to the license.txt file included.
 
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, version 2.0.
-
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License 2.0 for more details.
-
-// A copy of the GPL 2.0 should have been included with the program.
-// If not, see http://www.gnu.org/licenses/
-
-// Official SVN repository and contact information can be found at
-// http://code.google.com/p/dolphin-emu/
-#ifndef _X11_UTIL_H_
-#define _X11_UTIL_H_
+#pragma once
 
 #include <X11/Xlib.h>
 #include <X11/keysym.h>
@@ -45,5 +32,3 @@ public:
 	void DestroyXWindow(void);
 };
 #endif
-
-#endif