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/usb/storage/uas.c

@@ -799,7 +799,7 @@ static int uas_slave_configure(struct scsi_device *sdev)
 	if (devinfo->flags & US_FL_NO_REPORT_OPCODES)
 		sdev->no_report_opcodes = 1;
 
-	scsi_adjust_queue_depth(sdev, devinfo->qdepth - 2);
+	scsi_change_queue_depth(sdev, devinfo->qdepth - 2);
 	return 0;
 }