dp83640: use proper function to free transmit time stamping packets

commit f5ff7cd1 upstream.

The previous commit enforces a new rule for handling the cloned packets
for transmit time stamping. These packets must not be freed using any other
function than skb_complete_tx_timestamp. This commit fixes the one and only
driver using this API.

The driver first appeared in v3.0.
Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/net/phy/dp83640.c

@@ -1067,7 +1067,7 @@ static void dp83640_txtstamp(struct phy_device *phydev,
 	struct dp83640_private *dp83640 = phydev->priv;
 
 	if (!dp83640->hwts_tx_en) {
-		kfree_skb(skb);
+		skb_complete_tx_timestamp(skb, NULL);
 		return;
 	}
 	skb_queue_tail(&dp83640->tx_queue, skb);