nvme: host: unquiesce queue in nvme_kill_queues()

nvme: host: unquiesce queue in nvme_kill_queues()

When nvme_kill_queues() is run, queues may be in
quiesced state, so we forcibly unquiesce queues to avoid
blocking dispatch, and I/O hang can be avoided in
remove path.

Peviously we use blk_mq_start_stopped_hw_queues() as
counterpart of blk_mq_quiesce_queue(), now we have
introduced blk_mq_unquiesce_queue(), so use it explicitly.

Cc: [email protected]
Signed-off-by: Ming Lei <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>