[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/bluetooth/bpa10x.c b/drivers/bluetooth/bpa10x.c
index 9fca651..e8ebd5d 100644
--- a/drivers/bluetooth/bpa10x.c
+++ b/drivers/bluetooth/bpa10x.c
@@ -231,7 +231,7 @@
 		cr = (struct usb_ctrlrequest *) urb->setup_packet;
 		cr->wLength = __cpu_to_le16(skb->len);
 
-		memcpy(urb->transfer_buffer, skb->data, skb->len);
+		skb_copy_from_linear_data(skb, urb->transfer_buffer, skb->len);
 		urb->transfer_buffer_length = skb->len;
 
 		err = usb_submit_urb(urb, GFP_ATOMIC);
@@ -250,7 +250,7 @@
 		skb = skb_dequeue(&data->tx_queue);
 
 	if (skb) {
-		memcpy(urb->transfer_buffer, skb->data, skb->len);
+		skb_copy_from_linear_data(skb, urb->transfer_buffer, skb->len);
 		urb->transfer_buffer_length = skb->len;
 
 		err = usb_submit_urb(urb, GFP_ATOMIC);