net: fix network driver ndo_start_xmit() return values (part 1)

Fix up drivers that return an errno value to qdisc_restart(), causing
qdisc_restart() to print a warning and requeue/retransmit the skb.

- xpnet: memory allocation error, intention is to drop
- ethoc: oversized packet, packet must be dropped
- ibmlana: skb freed: use after free
- rrunner: skb freed: use after free

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/misc/sgi-xp/xpnet.c

@@ -450,7 +450,8 @@ xpnet_dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
 			 "packet\n", sizeof(struct xpnet_pending_msg));
 
 		dev->stats.tx_errors++;
-		return -ENOMEM;
+		dev_kfree_skb(skb);
+		return NETDEV_TX_OK;
 	}
 
 	/* get the beginning of the first cacheline and end of last */