[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/chelsio/sge.c b/drivers/net/chelsio/sge.c
index 43e92f9..1be1bbd 100644
--- a/drivers/net/chelsio/sge.c
+++ b/drivers/net/chelsio/sge.c
@@ -1062,7 +1062,7 @@
 					    pci_unmap_addr(ce, dma_addr),
 					    pci_unmap_len(ce, dma_len),
 					    PCI_DMA_FROMDEVICE);
-		memcpy(skb->data, ce->skb->data, len);
+		skb_copy_from_linear_data(ce->skb, skb->data, len);
 		pci_dma_sync_single_for_device(pdev,
 					       pci_unmap_addr(ce, dma_addr),
 					       pci_unmap_len(ce, dma_len),