Replace all include guard ifdefs with "#pragma once"

Source/Core/DolphinWX/ARCodeAddEdit.h

@@ -2,8 +2,7 @@
 // Licensed under GPLv2
 // Refer to the license.txt file included.
 
-#ifndef __ARCODE_ADDEDIT_h__
-#define __ARCODE_ADDEDIT_h__
+#pragma once
 
 #include <wx/wx.h>
 #include <wx/spinctrl.h>
@@ -40,4 +39,3 @@ class CARCodeAddEdit : public wxDialog
 		int selection;
 
 };
-#endif // __PATCH_ADDEDIT_h__