[SK_BUFF]: Introduce skb_copy_to_linear_data{_offset}

To clearly state the intent of copying to linear sk_buffs, _offset being a
overly long variant but interesting for the sake of saving some bytes.

Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
diff --git a/drivers/net/atari_bionet.c b/drivers/net/atari_bionet.c
index 13dbed3..3d87bd2 100644
--- a/drivers/net/atari_bionet.c
+++ b/drivers/net/atari_bionet.c
@@ -550,7 +550,8 @@
 
 			/* 'skb->data' points to the start of sk_buff data area.
 			 */
-			memcpy(skb->data, nic_packet->buffer, pkt_len);
+			skb_copy_to_linear_data(skb, nic_packet->buffer,
+						pkt_len);
 			skb->protocol = eth_type_trans( skb, dev );
 			netif_rx(skb);
 			dev->last_rx = jiffies;