scsi: provide a generic change_queue_type method

Most drivers use exactly the same implementation, so provide it as a
library function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
diff --git a/drivers/scsi/esas2r/esas2r_main.c b/drivers/scsi/esas2r/esas2r_main.c
index 45aa684..be09c62 100644
--- a/drivers/scsi/esas2r/esas2r_main.c
+++ b/drivers/scsi/esas2r/esas2r_main.c
@@ -258,7 +258,7 @@
 	.slave_alloc			= esas2r_slave_alloc,
 	.slave_destroy			= esas2r_slave_destroy,
 	.change_queue_depth		= esas2r_change_queue_depth,
-	.change_queue_type		= esas2r_change_queue_type,
+	.change_queue_type		= scsi_change_queue_type,
 	.max_sectors			= 0xFFFF,
 };
 
@@ -1268,24 +1268,6 @@
 	return dev->queue_depth;
 }
 
-int esas2r_change_queue_type(struct scsi_device *dev, int type)
-{
-	esas2r_log(ESAS2R_LOG_INFO, "change_queue_type %p, %d", dev, type);
-
-	if (dev->tagged_supported) {
-		scsi_set_tag_type(dev, type);
-
-		if (type)
-			scsi_activate_tcq(dev, dev->queue_depth);
-		else
-			scsi_deactivate_tcq(dev, dev->queue_depth);
-	} else {
-		type = 0;
-	}
-
-	return type;
-}
-
 int esas2r_slave_alloc(struct scsi_device *dev)
 {
 	return 0;