b43legacy: Do not return TX_BUSY from op_tx

Never return TX_BUSY from op_tx. It doesn't make sense to return
TX_BUSY, if we can not transmit the packet.
Drop the packet and return TX_OK.

Signed-off-by: Michael Buesch <[e-mail]>
Signed-off-by: John W. Linville <[e-mail]>

drivers/net/wireless/b43legacy/main.c

···
 	} else
 		err = b43legacy_dma_tx(dev, skb, ctl);
 out:
-	if (unlikely(err))
-		return NETDEV_TX_BUSY;
+	if (unlikely(err)) {
+		/* Drop the packet. */
+		dev_kfree_skb_any(skb);
+	}
 	return NETDEV_TX_OK;
 }