gsnull: Remove GSsetWindowInfo

PCSX2 doesn't actually use it.

GSnull also seems a bit behind the current GS plugin API - perhaps it
should be removed.

common/include/PS2Edefs.h

@@ -220,16 +220,6 @@ typedef struct _GSdriverInfo {
 	void *common;
 } GSdriverInfo;
 
-#ifdef _WIN32
-// TODO: Only GSNull uses this? Yet it doesn't seem to be used by PCSX2.
-#include <windows.h>
-typedef struct _winInfo { // unsupported values must be set to zero
-	HWND hWnd;
-	HMENU hMenu;
-	HWND hStatusWnd;
-} winInfo;
-#endif
-
 #ifdef __cplusplus
 extern "C" {
 #endif

plugins/GSnull/Windows/GS.def

@@ -33,7 +33,6 @@ EXPORTS
 	GSreset					@28
 	GSwriteCSR				@29
 	GSgetDriverInfo			@30
-	GSsetWindowInfo			@31
 	GSfreeze				@32
 	GSconfigure				@33
 	GSabout					@34

plugins/GSnull/Windows/GSwin.cpp

@@ -68,8 +68,3 @@ void GSProcessMessages()
 void HandleKeyEvent(keyEvent *ev)
 {
 }
-
-EXPORT_C_(s32) GSsetWindowInfo(winInfo *info)
-{
-	return 0;
-}