ublk: don't get ublk device reference in ublk_abort_queue()

ublk_abort_queue() is called in ublk_daemon_monitor_work(), in which
it is guaranteed that the device is live because monitor work is
canceled when removing device, so no need to get the device reference.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20231009093324.957829-2-ming.lei@redhat.com


Signed-off-by: Jens Axboe <axboe@kernel.dk>