scsi: drop reason argument from ->change_queue_depth

Drop the now unused reason argument from the ->change_queue_depth method.
Also add a return value to scsi_adjust_queue_depth, and rename it to
scsi_change_queue_depth now that it can be used as the default
->change_queue_depth implementation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

drivers/scsi/pmcraid.c

@@ -285,23 +285,15 @@ static void pmcraid_slave_destroy(struct scsi_device *scsi_dev)
  * pmcraid_change_queue_depth - Change the device's queue depth
  * @scsi_dev: scsi device struct
  * @depth: depth to set
- * @reason: calling context
  *
  * Return value
  *	actual depth set
  */
-static int pmcraid_change_queue_depth(struct scsi_device *scsi_dev, int depth,
-				      int reason)
+static int pmcraid_change_queue_depth(struct scsi_device *scsi_dev, int depth)
 {
-	if (reason != SCSI_QDEPTH_DEFAULT)
-		return -EOPNOTSUPP;
-
 	if (depth > PMCRAID_MAX_CMD_PER_LUN)
 		depth = PMCRAID_MAX_CMD_PER_LUN;
-
-	scsi_adjust_queue_depth(scsi_dev, depth);
-
-	return scsi_dev->queue_depth;
+	return scsi_change_queue_depth(scsi_dev, depth);
 }
 
 /**