md-cluster: free md_cluster_info if node leave cluster

BugLink: http://bugs.launchpad.net/bugs/1745052

[ Upstream commit 9c8043f3 ]

To avoid memory leak, we need to free the cinfo which
is allocated when node join cluster.
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

drivers/md/md-cluster.c

@@ -821,6 +821,7 @@ static int leave(struct mddev *mddev)
 	lockres_free(cinfo->no_new_dev_lockres);
 	lockres_free(cinfo->bitmap_lockres);
 	dlm_release_lockspace(cinfo->lockspace, 2);
+	kfree(cinfo);
 	return 0;
 }