mac80211: set assoc flag to bss_conf

Only BSS_CHANGED_ASSOC was set in the 'changed' bitmask. Assignment  to
bss_conf.assoc was absent.
This patch assign value to  bss_conf.assoc according the association state.
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/ieee80211_sta.c

@@ -492,6 +492,7 @@ static void ieee80211_set_associated(struct net_device *dev,
 	ifsta->last_probe = jiffies;
 	ieee80211_led_assoc(local, assoc);
 
+	sdata->bss_conf.assoc = assoc;
 	ieee80211_bss_info_change_notify(sdata, changed);
 }