mac80211: deauth before flushing STA information

mac80211: deauth before flushing STA information

Even after commit "mac80211: deauth when interface is marked down"
(e327b847 on Linus tree), userspace still isn't notified when interface
goes down. There isn't a problem with this commit, but because of other
code changes it doesn't work on kernels >= 2.6.28 (works if same/similar
change applied on 2.6.27 for example).

The issue is as follows: after commit "mac80211: restructure disassoc/deauth
flows" in 2.6.28, the call to ieee80211_sta_deauthenticate added by
commit e327b847 will not work: because we do sta_info_flush(local, sdata)
inside ieee80211_stop (iface.c), all stations in interface are cleared, so
when calling ieee80211_sta_deauthenticate->ieee80211_set_disassoc (mlme.c),
inside ieee80211_set_disassoc we have this in the beginning:

         sta = sta_info_get(local, ifsta->bssid);
         if (!sta) {

The !sta check triggers, thus the function returns early and
ieee80211_sta_send_apinfo(sdata, ifsta) later isn't called, so
wpa_supplicant/userspace isn't notified with SIOCGIWAP.

This commit moves deauthentication to before flushing STA info
(sta_info_flush), thus the above can't happen and userspace is really
notified when interface goes down.

Signed-off-by: Herton Ronaldo Krzesinski <herton@mandriva.com.br>
Signed-off-by: John W. Linville <linville@tuxdriver.com>