[SK_BUFF]: Introduce skb_copy_from_linear_data{_offset}

To clearly state the intent of copying from 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@redhat.com>
diff --git a/drivers/usb/net/pegasus.c b/drivers/usb/net/pegasus.c
index 13f70e0..1ad4ee5 100644
--- a/drivers/usb/net/pegasus.c
+++ b/drivers/usb/net/pegasus.c
@@ -889,7 +889,7 @@
 	netif_stop_queue(net);
 
 	((__le16 *) pegasus->tx_buff)[0] = cpu_to_le16(l16);
-	memcpy(pegasus->tx_buff + 2, skb->data, skb->len);
+	skb_copy_from_linear_data(skb, pegasus->tx_buff + 2, skb->len);
 	usb_fill_bulk_urb(pegasus->tx_urb, pegasus->usb,
 			  usb_sndbulkpipe(pegasus->usb, 2),
 			  pegasus->tx_buff, count,