ath5k: fix return values from ath5k_tx

Should return NETDEV_TX_{OK,BUSY} instead of 0,-1 (this doesn't change
any current functionality).

Changes-licensed-under: 3-Clause-BSD
Reported-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath5k/base.c

@@ -2644,7 +2644,7 @@ ath5k_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
 		if (skb_headroom(skb) < padsize) {
 			ATH5K_ERR(sc, "tx hdrlen not %%4: %d not enough"
 				  " headroom to pad %d\n", hdrlen, padsize);
-			return -1;
+			return NETDEV_TX_BUSY;
 		}
 		skb_push(skb, padsize);
 		memmove(skb->data, skb->data+padsize, hdrlen);
@@ -2655,7 +2655,7 @@ ath5k_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
 		ATH5K_ERR(sc, "no further txbuf available, dropping packet\n");
 		spin_unlock_irqrestore(&sc->txbuflock, flags);
 		ieee80211_stop_queue(hw, skb_get_queue_mapping(skb));
-		return -1;
+		return NETDEV_TX_BUSY;
 	}
 	bf = list_first_entry(&sc->txbuf, struct ath5k_buf, list);
 	list_del(&bf->list);
@@ -2673,10 +2673,10 @@ ath5k_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
 		sc->txbuf_len++;
 		spin_unlock_irqrestore(&sc->txbuflock, flags);
 		dev_kfree_skb_any(skb);
-		return 0;
+		return NETDEV_TX_OK;
 	}
 
-	return 0;
+	return NETDEV_TX_OK;
 }
 
 static int