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/include/scsi/libsas.h b/include/scsi/libsas.h
index ef7872c..1f8b33e 100644
--- a/include/scsi/libsas.h
+++ b/include/scsi/libsas.h
@@ -704,8 +704,7 @@
 extern int sas_queuecommand(struct Scsi_Host * ,struct scsi_cmnd *);
 extern int sas_target_alloc(struct scsi_target *);
 extern int sas_slave_configure(struct scsi_device *);
-extern int sas_change_queue_depth(struct scsi_device *, int new_depth,
-				  int reason);
+extern int sas_change_queue_depth(struct scsi_device *, int new_depth);
 extern int sas_change_queue_type(struct scsi_device *, int qt);
 extern int sas_bios_param(struct scsi_device *,
 			  struct block_device *,