md: fix sync_completed reporting for very large drives (>2TB)

The values exported in the sync_completed file are unsigned long, which
overflows with very large drives, resulting in wrong values reported.

Since sync_completed uses sectors as unit, we'll start getting wrong
values with components larger than 2TB.

This patch simply replaces the use of unsigned long by unsigned long long.
Signed-off-by: Rémi Rérolle <rrerolle@lacie.com>
Signed-off-by: NeilBrown <neilb@suse.de>

drivers/md/md.c

@@ -3918,7 +3918,7 @@ static struct md_sysfs_entry md_sync_speed = __ATTR_RO(sync_speed);
 static ssize_t
 sync_completed_show(mddev_t *mddev, char *page)
 {
-	unsigned long max_sectors, resync;
+	unsigned long long max_sectors, resync;
 
 	if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
 		return sprintf(page, "none\n");
@@ -3929,7 +3929,7 @@ sync_completed_show(mddev_t *mddev, char *page)
 		max_sectors = mddev->dev_sectors;
 
 	resync = mddev->curr_resync_completed;
-	return sprintf(page, "%lu / %lu\n", resync, max_sectors);
+	return sprintf(page, "%llu / %llu\n", resync, max_sectors);
 }
 
 static struct md_sysfs_entry md_sync_completed = __ATTR_RO(sync_completed);