md: Make mddev->array_size sector-based.

This patch renames the array_size field of struct mddev_s to array_sectors
and converts all instances to use units of 512 byte sectors instead of 1k
blocks.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/multipath.c b/drivers/md/multipath.c
index 541cbe3..c4779cc 100644
--- a/drivers/md/multipath.c
+++ b/drivers/md/multipath.c
@@ -504,7 +504,7 @@
 	/*
 	 * Ok, everything is just fine now
 	 */
-	mddev->array_size = mddev->size;
+	mddev->array_sectors = mddev->size * 2;
 
 	mddev->queue->unplug_fn = multipath_unplug;
 	mddev->queue->backing_dev_info.congested_fn = multipath_congested;