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>
diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
index 670b75a..4d1b722 100644
--- a/drivers/target/loopback/tcm_loop.c
+++ b/drivers/target/loopback/tcm_loop.c
@@ -110,19 +110,6 @@
  */
 struct device *tcm_loop_primary;
 
-/*
- * Copied from drivers/scsi/libfc/fc_fcp.c:fc_change_queue_depth() and
- * drivers/scsi/libiscsi.c:iscsi_change_queue_depth()
- */
-static int tcm_loop_change_queue_depth(
-	struct scsi_device *sdev,
-	int depth,
-	int reason)
-{
-	scsi_adjust_queue_depth(sdev, depth);
-	return sdev->queue_depth;
-}
-
 static void tcm_loop_submission_work(struct work_struct *work)
 {
 	struct tcm_loop_cmd *tl_cmd =
@@ -397,7 +384,7 @@
 	.proc_name		= "tcm_loopback",
 	.name			= "TCM_Loopback",
 	.queuecommand		= tcm_loop_queuecommand,
-	.change_queue_depth	= tcm_loop_change_queue_depth,
+	.change_queue_depth	= scsi_change_queue_depth,
 	.change_queue_type	= scsi_change_queue_type,
 	.eh_abort_handler = tcm_loop_abort_task,
 	.eh_device_reset_handler = tcm_loop_device_reset,