ublk_drv: remove nr_aborted_queues from ublk_device

No one uses 'nr_aborted_queues' any more, so remove it.

Reviewed-by: ZiyangZhang <ZiyangZhang@linux.alibaba.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230106041711.914434-2-ming.lei@redhat.com


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