mac80211: Enable power save after receiving NULL packet ACK

Trigger dynamic_ps_timer to re-evaluate power saving once a null
function packet (with PM = 1) is ACKed, otherwise dynamic PS is
not enabled at that point.

Signed-off-by: Bassem Dawood <bassem@morsemicro.com>
Link: https://lore.kernel.org/r/20210227055815.14838-1-bassem@morsemicro.com
[reformatting]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/status.c

@@ -1006,12 +1006,11 @@ static void __ieee80211_tx_status(struct ieee80211_hw *hw,
 	    ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS) &&
 	    !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
 	    local->ps_sdata && !(local->scanning)) {
-		if (info->flags & IEEE80211_TX_STAT_ACK) {
+		if (info->flags & IEEE80211_TX_STAT_ACK)
 			local->ps_sdata->u.mgd.flags |=
 					IEEE80211_STA_NULLFUNC_ACKED;
-		} else
-			mod_timer(&local->dynamic_ps_timer, jiffies +
-					msecs_to_jiffies(10));
+		mod_timer(&local->dynamic_ps_timer,
+			  jiffies + msecs_to_jiffies(10));
 	}
 
 	ieee80211_report_used_skb(local, skb, false);