of_changeset_attach_node
rc = of_changeset_attach_node(ocs, dn);
ret = of_changeset_attach_node(&cs, dn);
ret = of_changeset_attach_node(ocs, np);
ret = of_changeset_attach_node(&ovcs->cset, tchild);
unittest(!of_changeset_attach_node(&chgset, n1), "fail attach n1\n");
unittest(!of_changeset_attach_node(&chgset, n2), "fail attach n2\n");
unittest(!of_changeset_attach_node(&chgset, n21), "fail attach n21\n");
ret = of_changeset_attach_node(ocs, child);