loop: fix order of cleaning up the queue and freeing the tagset

We must release the queue before freeing the tagset.

Fixes: 1c99502f ("loop: use blk_mq_alloc_disk and blk_cleanup_disk")
Reported-by: Bruno Goncalves <bgoncalv@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>