[PATCH] md: fix bug where spares don't always get rebuilt properly when they become live

If save_raid_disk is >= 0, then the device could be a device that is already
in sync that is being re-added.  So we need to default this value to -1.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/md/md.c

@@ -2003,6 +2003,7 @@ static mdk_rdev_t *md_import_device(dev_t newdev, int super_format, int super_mi
 	kobject_init(&rdev->kobj);
 
 	rdev->desc_nr = -1;
+	rdev->saved_raid_disk = -1;
 	rdev->flags = 0;
 	rdev->data_offset = 0;
 	rdev->sb_events = 0;