xwayland: Handle NULL xwl_seat in xwl_seat_can_emulate_pointer_warp
This can happen e.g. with weston's headless backend. Reviewed-by: Olivier Fourdan <ofourdan@redhat.com>
This can happen e.g. with weston's headless backend. Reviewed-by: Olivier Fourdan <ofourdan@redhat.com>