wl12xx: do not set queue_mapping directly

It is preferred to use the setter that to set queue_mapping directly.
This also helps backporting in compat-wireless.
Signed-off-by: NHauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: NLuciano Coelho <coelho@ti.com>

drivers/net/wireless/wl12xx/main.c

@@ -1294,7 +1294,7 @@ static struct sk_buff *wl12xx_alloc_dummy_packet(struct wl1271 *wl)
 	skb->priority = WL1271_TID_MGMT;
 
 	/* Initialize all fields that might be used */
-	skb->queue_mapping = 0;
+	skb_set_queue_mapping(skb, 0);
 	memset(IEEE80211_SKB_CB(skb), 0, sizeof(struct ieee80211_tx_info));
 
 	return skb;