[PATCH] md: fix calculation of ->degraded for multipath and raid10

Two less-used md personalities have bugs in the calculation of ->degraded (the
extent to which the array is degraded).

Signed-off-by: Neil Brown <neilb@suse.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/md/multipath.c b/drivers/md/multipath.c
index 171ff41..a6260f0 100644
--- a/drivers/md/multipath.c
+++ b/drivers/md/multipath.c
@@ -501,7 +501,7 @@
 			mdname(mddev));
 		goto out_free_conf;
 	}
-	mddev->degraded = conf->raid_disks = conf->working_disks;
+	mddev->degraded = conf->raid_disks - conf->working_disks;
 
 	conf->pool = mempool_create_kzalloc_pool(NR_RESERVED_BUFS,
 						 sizeof(struct multipath_bh));