So that Wine doesn't have to send an extra WM_NULL message when
wait_graphics_driver_ready() is later called in
EnumDisplayDevicesW(). Also, it avoids a deadlock when
wait_graphics_driver_ready() is used in later patches.
Signed-off-by: Zhiyi Zhang <zzhang@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>