r8169: convert to SKB paged frag API.

Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
Cc: Realtek linux nic maintainers <nic_swsd@realtek.com>
Cc: Francois Romieu <romieu@fr.zoreil.com>
Cc: netdev@vger.kernel.org
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/realtek/r8169.c

@@ -5027,7 +5027,7 @@ static int rtl8169_xmit_frags(struct rtl8169_private *tp, struct sk_buff *skb,
 
 		txd = tp->TxDescArray + entry;
 		len = frag->size;
-		addr = ((void *) page_address(frag->page)) + frag->page_offset;
+		addr = skb_frag_address(frag);
 		mapping = dma_map_single(d, addr, len, DMA_TO_DEVICE);
 		if (unlikely(dma_mapping_error(d, mapping))) {
 			if (net_ratelimit())