block: remove QUEUE_FLAG_SCSI_PASSTHROUGH

Export scsi_device_from_queue for use with pktcdvd and use that instead
of the otherwise unused QUEUE_FLAG_SCSI_PASSTHROUGH queue flag.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20211021060607.264371-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
5 files changed