md: change ITERATE_RDEV to rdev_for_each

As this is more in line with common practice in the kernel.  Also swap the
args around to be more like list_for_each.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/md/linear.c b/drivers/md/linear.c
index 3dac1cf..0b85117 100644
--- a/drivers/md/linear.c
+++ b/drivers/md/linear.c
@@ -122,7 +122,7 @@
 	cnt = 0;
 	conf->array_size = 0;
 
-	ITERATE_RDEV(mddev,rdev,tmp) {
+	rdev_for_each(rdev, tmp, mddev) {
 		int j = rdev->raid_disk;
 		dev_info_t *disk = conf->disks + j;