gianfar: Carefully free skbs in functions called by netpoll.

commit c9974ad4 upstream.

netpoll can call functions in hard irq context that are ordinarily
called in lesser contexts.  For those functions use dev_kfree_skb_any
and dev_consume_skb_any so skbs are freed safely from hard irq
context.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: use only dev_kfree_skb() and not dev_consume_skb_any()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/net/ethernet/freescale/gianfar.c

@@ -2092,10 +2092,10 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev)
 		skb_new = skb_realloc_headroom(skb, GMAC_FCB_LEN);
 		if (!skb_new) {
 			dev->stats.tx_errors++;
-			kfree_skb(skb);
+			dev_kfree_skb_any(skb);
 			return NETDEV_TX_OK;
 		}
-		kfree_skb(skb);
+		dev_kfree_skb_any(skb);
 		skb = skb_new;
 	}