scsi: don't set tagging state from scsi_adjust_queue_depth

Remove the tagged argument from scsi_adjust_queue_depth, and just let it
handle the queue depth.  For most drivers those two are fairly separate,
given that most modern drivers don't care about the SCSI "tagged" status
of a command at all, and many old drivers allow queuing of multiple
untagged commands in the driver.

Instead we start out with the ->simple_tags flag set before calling
->slave_configure, which is how all drivers actually looking at
->simple_tags except for one worke anyway.  The one other case looks
broken, but I've kept the behavior as-is for now.

Except for that we only change ->simple_tags from the ->change_queue_type,
and when rejecting a tag message in a single driver, so keeping this
churn out of scsi_adjust_queue_depth is a clear win.

Now that the usage of scsi_adjust_queue_depth is more obvious we can
also remove all the trivial instances in ->slave_alloc or ->slave_configure
that just set it to the cmd_per_lun default.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/BusLogic.c

@@ -2327,12 +2327,12 @@ static int blogic_slaveconfig(struct scsi_device *dev)
 		if (qdepth == 0)
 			qdepth = BLOGIC_MAX_AUTO_TAG_DEPTH;
 		adapter->qdepth[tgt_id] = qdepth;
-		scsi_adjust_queue_depth(dev, MSG_SIMPLE_TAG, qdepth);
+		scsi_adjust_queue_depth(dev, qdepth);
 	} else {
 		adapter->tagq_ok &= ~(1 << tgt_id);
 		qdepth = adapter->untag_qdepth;
 		adapter->qdepth[tgt_id] = qdepth;
-		scsi_adjust_queue_depth(dev, 0, qdepth);
+		scsi_adjust_queue_depth(dev, qdepth);
 	}
 	qdepth = 0;
 	for (tgt_id = 0; tgt_id < adapter->maxdev; tgt_id++)