mac80211: remove disconnected APs from BSS table

In some cases, after a sudden AP disappearing and reconnection to
another AP in the same ESS, user space gets the old AP in scan
results (cached). User space may decide to roam to that old AP
which will cause a disconnection and longer recovery.
Remove APs that are probably out of range from BSS table.
Signed-off-by: David Spinadel <david.spinadel@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/mlme.c

@@ -2399,6 +2399,11 @@ static void __ieee80211_disconnect(struct ieee80211_sub_if_data *sdata)
 		return;
 	}
 
+	/* AP is probably out of range (or not reachable for another reason) so
+	 * remove the bss struct for that AP.
+	 */
+	cfg80211_unlink_bss(local->hw.wiphy, ifmgd->associated);
+
 	ieee80211_set_disassoc(sdata, IEEE80211_STYPE_DEAUTH,
 			       WLAN_REASON_DISASSOC_DUE_TO_INACTIVITY,
 			       true, frame_buf);