[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/myri10ge/myri10ge.c b/drivers/net/myri10ge/myri10ge.c
index e4b69a0..16e3c43 100644
--- a/drivers/net/myri10ge/myri10ge.c
+++ b/drivers/net/myri10ge/myri10ge.c
@@ -879,7 +879,7 @@
 	 * skb_pull() (for ether_pad and eth_type_trans()) requires
 	 * the beginning of the packet in skb_headlen(), move it
 	 * manually */
-	memcpy(skb->data, va, hlen);
+	skb_copy_to_linear_data(skb, va, hlen);
 	skb_shinfo(skb)->frags[0].page_offset += hlen;
 	skb_shinfo(skb)->frags[0].size -= hlen;
 	skb->data_len -= hlen;