[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/wan/pc300_drv.c b/drivers/net/wan/pc300_drv.c
index 8ba75bb..999bf71 100644
--- a/drivers/net/wan/pc300_drv.c
+++ b/drivers/net/wan/pc300_drv.c
@@ -1759,7 +1759,7 @@
 	skb->pkt_type = PACKET_HOST;
 	skb->len = 10 + skb_main->len;
 
-	memcpy(skb->data, dev->name, 5);
+	skb_copy_to_linear_data(skb, dev->name, 5);
 	skb->data[5] = '[';
 	skb->data[6] = rx_tx;
 	skb->data[7] = ']';