Xwayland uses the device private to point to the `xwl_seat`.
Device may be removed at any time, including on suspend.
On resume, if the DIX code ends up calling a function that requires the
`xwl_seat` such as `xwl_set_cursor()` we may end up pointing at random
data.
Make sure the clear the device private data on removal so that we don't
try to use it and crash later.
Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
https://gitlab.freedesktop.org/xorg/xserver/issues/709
(cherry picked from commit 4195e80356)
3aa31823db