[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/fore200e.c b/drivers/atm/fore200e.c
index 5f70219..2bf723a 100644
--- a/drivers/atm/fore200e.c
+++ b/drivers/atm/fore200e.c
@@ -1176,7 +1176,7 @@
 	return -ENOMEM;
     } 
 
-    do_gettimeofday(&skb->stamp);
+    __net_timestamp(skb);
     
 #ifdef FORE200E_52BYTE_AAL0_SDU
     if (cell_header) {