[NET]: Store skb->timestamp as offset to a base timestamp

Reduces skb size by 8 bytes on 64-bit.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/atm/eni.c b/drivers/atm/eni.c
index 10da369..c13c4d7 100644
--- a/drivers/atm/eni.c
+++ b/drivers/atm/eni.c
@@ -537,7 +537,7 @@
 		return 0;
 	}
 	skb_put(skb,length);
-	skb->stamp = eni_vcc->timestamp;
+	skb_set_timestamp(skb, &eni_vcc->timestamp);
 	DPRINTK("got len %ld\n",length);
 	if (do_rx_dma(vcc,skb,1,length >> 2,length >> 2)) return 1;
 	eni_vcc->rxing++;