ubi_detach_mtd_dev
ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
err = ubi_detach_mtd_dev(ubi_num, 0);
int ubi_detach_mtd_dev(int ubi_num, int anyway);