staging/lustre/ldlm: Unregister ldlm namespace from sysfs on free

ldlm_namespace_sysfs_unregister needs to be called ldlm_namespace_free_post
so that we don't have this dangling object there after the namespace
has disappeared.
Signed-off-by: NOleg Drokin <green@linuxhacker.ru>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/ldlm/ldlm_resource.c

@@ -939,6 +939,7 @@ void ldlm_namespace_free_post(struct ldlm_namespace *ns)
 	ldlm_pool_fini(&ns->ns_pool);
 
 	ldlm_namespace_debugfs_unregister(ns);
+	ldlm_namespace_sysfs_unregister(ns);
 	cfs_hash_putref(ns->ns_rs_hash);
 	/* Namespace \a ns should be not on list at this time, otherwise
 	 * this will cause issues related to using freed \a ns in poold