ieee80211_add_wmm_info_ie
pos = ieee80211_add_wmm_info_ie(pos, 0); /* U-APSD not in use */
u8 *ieee80211_add_wmm_info_ie(u8 *buf, u8 qosinfo);
ieee80211_add_wmm_info_ie(skb_put(skb, 9), qos_info);
pos = ieee80211_add_wmm_info_ie(skb_put(skb, 9), qos_info);
ieee80211_add_wmm_info_ie(skb_put(skb, 9), 0); /* no U-APSD */