int __qeth_ref_ip_on_card (struct qeth_card * card, struct qeth_ipaddr * todo, struct qeth_ipaddr ** __addr);
reference to/from an IP address that is already registered on the card.
0 address was on card and its reference count has been adjusted, but is still > 0, so nothing has to be done also returns 0 if card was not on card and the todo was to delete the address -> there is also nothing to be done 1 address was not on card and the todo is to add it to the card's ip list -1 address was on card and its reference count has been decremented to <= 0 by the todo -> address must be removed from card