scsi: core: Remove reserved request time-out handling

The SCSI core code does not currently support reserved commands. As such,
requests which time-out would never be reserved, and scsi_timeout()
'reserved' arg should never be set.

Remove handling for reserved requests, drop the wrapper scsi_timeout()
as it now just calls scsi_times_out() always, and finally rename
scsi_times_out() -> scsi_timeout() to match the blk_mq_ops method name.

Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/1657109034-206040-2-git-send-email-john.garry@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>