ocfs2: Proper cleanup in case of error in ocfs2_register_hb_callbacks()

If ocfs2_register_hb_callbacks() succeeds on its first callback but fails
its second, it doesn't release the first on the way out. Fix that.

While we're at it, o2hb_unregister_callback() never returns anything but
0, so let's make it void.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/ocfs2/heartbeat.c b/fs/ocfs2/heartbeat.c
index 8fc52d6..b25ef63 100644
--- a/fs/ocfs2/heartbeat.c
+++ b/fs/ocfs2/heartbeat.c
@@ -164,8 +164,10 @@
 	}
 
 	status = o2hb_register_callback(&osb->osb_hb_up);
-	if (status < 0)
+	if (status < 0) {
 		mlog_errno(status);
+		o2hb_unregister_callback(&osb->osb_hb_down);
+	}
 
 bail:
 	return status;
@@ -173,18 +175,11 @@
 
 void ocfs2_clear_hb_callbacks(struct ocfs2_super *osb)
 {
-	int status;
-
 	if (ocfs2_mount_local(osb))
 		return;
 
-	status = o2hb_unregister_callback(&osb->osb_hb_down);
-	if (status < 0)
-		mlog_errno(status);
-
-	status = o2hb_unregister_callback(&osb->osb_hb_up);
-	if (status < 0)
-		mlog_errno(status);
+	o2hb_unregister_callback(&osb->osb_hb_down);
+	o2hb_unregister_callback(&osb->osb_hb_up);
 }
 
 void ocfs2_stop_heartbeat(struct ocfs2_super *osb)