r8169: remove not needed call to dma_sync_single_for_device

DMA_API_HOWTO.txt includes an example explaining when
dma_sync_single_for_device() is not needed, and that example matches
our use case. The buffer isn't changed by the CPU and direction is
DMA_FROM_DEVICE, so we can remove the call to
dma_sync_single_for_device().
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/realtek/r8169_main.c

@@ -5785,7 +5785,6 @@ static struct sk_buff *rtl8169_try_rx_copy(void *data,
 	skb = napi_alloc_skb(&tp->napi, pkt_size);
 	if (skb)
 		skb_copy_to_linear_data(skb, data, pkt_size);
-	dma_sync_single_for_device(d, addr, pkt_size, DMA_FROM_DEVICE);
 
 	return skb;
 }