pktcdvd: remove queue_lock around blk_queue_max_hw_sectors

blk_queue_max_hw_sectors can't do anything with queue_lock protection
so don't hold it.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>