[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/net/tulip/de2104x.c b/drivers/net/tulip/de2104x.c
index 8a7effa..d19f856 100644
--- a/drivers/net/tulip/de2104x.c
+++ b/drivers/net/tulip/de2104x.c
@@ -449,8 +449,8 @@
 		} else {
 			pci_dma_sync_single_for_cpu(de->pdev, mapping, len, PCI_DMA_FROMDEVICE);
 			skb_reserve(copy_skb, RX_OFFSET);
-			memcpy(skb_put(copy_skb, len), skb->data, len);
-
+			skb_copy_from_linear_data(skb, skb_put(copy_skb, len),
+						  len);
 			pci_dma_sync_single_for_device(de->pdev, mapping, len, PCI_DMA_FROMDEVICE);
 
 			/* We'll reuse the original ring buffer. */