ath9k: fix more-data flag for buffered multicast packets

The flag needs to be cleared for the last packet in the list, not the
first one. Fixes some issues with multicast packet loss for powersave
clients connected to an ath9k AP.
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/ath/ath9k/xmit.c

@@ -2436,7 +2436,6 @@ void ath_tx_cabq(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 		.txq = sc->beacon.cabq
 	};
 	struct ath_tx_info info = {};
-	struct ieee80211_hdr *hdr;
 	struct ath_buf *bf_tail = NULL;
 	struct ath_buf *bf;
 	LIST_HEAD(bf_q);
@@ -2480,15 +2479,10 @@ void ath_tx_cabq(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 	if (list_empty(&bf_q))
 		return;
 
-	bf = list_first_entry(&bf_q, struct ath_buf, list);
-	hdr = (struct ieee80211_hdr *) bf->bf_mpdu->data;
-
-	if (hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_MOREDATA)) {
-		hdr->frame_control &= ~cpu_to_le16(IEEE80211_FCTL_MOREDATA);
-		dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
-			sizeof(*hdr), DMA_TO_DEVICE);
-	}
+	bf = list_last_entry(&bf_q, struct ath_buf, list);
+	ath9k_set_moredata(sc, bf, false);
 
+	bf = list_first_entry(&bf_q, struct ath_buf, list);
 	ath_txq_lock(sc, txctl.txq);
 	ath_tx_fill_desc(sc, bf, txctl.txq, 0);
 	ath_tx_txqaddbuf(sc, txctl.txq, &bf_q, false);