Replace all include guard ifdefs with "#pragma once"

Source/Core/DolphinWX/Debugger/BreakpointDlg.h

@@ -2,9 +2,7 @@
 // Licensed under GPLv2
 // Refer to the license.txt file included.
 
-#ifndef __BREAKPOINTDLG_h__
-#define __BREAKPOINTDLG_h__
-
+#pragma once
 
 #include <wx/wx.h>
 
@@ -23,5 +21,3 @@ private:
 
 	DECLARE_EVENT_TABLE();
 };
-
-#endif