fec: fix race in transmit time stamping.

Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/fec.c

@@ -324,10 +324,10 @@ fec_enet_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 
 	fep->cur_tx = bdp;
 
-	spin_unlock_irqrestore(&fep->hw_lock, flags);
-
 	skb_tx_timestamp(skb);
 
+	spin_unlock_irqrestore(&fep->hw_lock, flags);
+
 	return NETDEV_TX_OK;
 }