Yes, we needn't this macro now. The only place it can be used is vty_interface_layer3.c:

static struct gsm_subscriber *get_subscr_by_argv(struct gsm_network *gsmnet,
                         const char *type,
                         const char *id)
{
    if (!strcmp(type, "extension"))
        return subscr_get_by_extension(gsmnet->subscr_group, id);
    else if (!strcmp(type, "imsi"))
        return subscr_get_by_imsi(gsmnet->subscr_group, id);
    else if (!strcmp(type, "tmsi"))
        return subscr_get_by_tmsi(gsmnet->subscr_group, id);
    else if (!strcmp(type, "id"))
        return subscr_get_by_id(gsmnet->subscr_group, atoi(id));

    return NULL;
}