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/scsi/bnx2fc/bnx2fc_fcoe.c b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c
index cc53797..386c2cf 100644
--- a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c
+++ b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c
@@ -2784,7 +2784,7 @@
 	.eh_target_reset_handler = bnx2fc_eh_target_reset, /* tgt reset */
 	.eh_host_reset_handler	= fc_eh_host_reset,
 	.slave_alloc		= fc_slave_alloc,
-	.change_queue_depth	= fc_change_queue_depth,
+	.change_queue_depth	= scsi_change_queue_depth,
 	.change_queue_type	= scsi_change_queue_type,
 	.this_id		= -1,
 	.cmd_per_lun		= 3,