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/3w-sas.c

@@ -191,17 +191,6 @@ static ssize_t twl_show_stats(struct device *dev,
 	return len;
 } /* End twl_show_stats() */
 
-/* This function will set a devices queue depth */
-static int twl_change_queue_depth(struct scsi_device *sdev, int queue_depth,
-				  int reason)
-{
-	if (reason != SCSI_QDEPTH_DEFAULT)
-		return -EOPNOTSUPP;
-
-	scsi_adjust_queue_depth(sdev, queue_depth);
-	return queue_depth;
-} /* End twl_change_queue_depth() */
-
 /* stats sysfs attribute initializer */
 static struct device_attribute twl_host_stats_attr = {
 	.attr = {
@@ -1588,7 +1577,7 @@ static struct scsi_host_template driver_template = {
 	.queuecommand		= twl_scsi_queue,
 	.eh_host_reset_handler	= twl_scsi_eh_reset,
 	.bios_param		= twl_scsi_biosparam,
-	.change_queue_depth	= twl_change_queue_depth,
+	.change_queue_depth	= scsi_change_queue_depth,
 	.can_queue		= TW_Q_LENGTH-2,
 	.slave_configure	= twl_slave_configure,
 	.this_id		= -1,