ieee80211_ess_cmp
RBT_GENERATE(ieee80211_ess_tree, ieee80211_ess_rbt, ess_rbt, ieee80211_ess_cmp);
int ieee80211_ess_cmp(const struct ieee80211_ess_rbt *,
RBT_PROTOTYPE(ieee80211_ess_tree, ieee80211_ess_rbt, ess_rbt, ieee80211_ess_cmp);