Fix return type of GetAsyncKeyState.

diff --git a/include/winuser.h b/include/winuser.h
index ff8dbe9..c12879a 100644
--- a/include/winuser.h
+++ b/include/winuser.h
@@ -3822,7 +3822,7 @@
 HWND        WINAPI GetActiveWindow(void);
 HWND        WINAPI GetAncestor(HWND,UINT);
 DWORD       WINAPI GetAppCompatFlags(HTASK);
-WORD        WINAPI GetAsyncKeyState(INT);
+SHORT       WINAPI GetAsyncKeyState(INT);
 HWND        WINAPI GetCapture(void);
 UINT        WINAPI GetCaretBlinkTime(void);
 BOOL        WINAPI GetCaretPos(LPPOINT);