md: md_unregister_thread should cope with being passed NULL

Mostly md_unregister_thread is only called when we know that the
thread is NULL, but sometimes we need to check first.  It is safer
to put the check inside md_unregister_thread itself.

Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 1 insertions, 2 deletions

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index d019a85547b4..81789fa7a023 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -4463,8 +4463,7 @@ static int run(mddev_t *mddev)
 
         return 0;
 abort:
-        if (mddev->thread)
-                md_unregister_thread(mddev->thread);
+        md_unregister_thread(mddev->thread);
         mddev->thread = NULL;
         if (conf) {
                 shrink_stripes(conf);