mac80211: HE STA disassoc due to QOS NULL not sent

In case of HE AP-STA link, ieee80211_send_nullfunc() will not
send the QOS NULL packet to check if AP is still associated.

In this case, probe_send_count will be non-zero and
ieee80211_sta_work() will later disassociate the AP, even
though no packet was ever sent.

Fix this by decrementing probe_send_count and not calling
ieee80211_send_nullfunc() in case of HE link, so that we
still wait for some time for the AP beacon to reappear and
don't disconnect right away.
Signed-off-by: Shay Bar <shay.bar@celeno.com>
Link: https://lore.kernel.org/r/20190703131848.22879-1-shay.bar@celeno.com
[clarify commit message]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/mlme.c

@@ -2512,6 +2512,9 @@ static void ieee80211_mgd_probe_ap_send(struct ieee80211_sub_if_data *sdata)
 
 	if (ieee80211_hw_check(&sdata->local->hw, REPORTS_TX_ACK_STATUS)) {
 		ifmgd->nullfunc_failed = false;
+		if (!(ifmgd->flags & IEEE80211_STA_DISABLE_HE))
+			ifmgd->probe_send_count--;
+		else
 			ieee80211_send_nullfunc(sdata->local, sdata, false);
 	} else {
 		int ssid_len;