r8169: kill eth_copy_and_sum()

It hasn't "summed" anything in over 7 years, and it's
just a straight mempcy ala skb_copy_to_linear_data()
so just get rid of it.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NFrancois Romieu <romieu@fr.zoreil.com>
Cc: Edward Hsu <edward_hsu@realtek.com.tw>

drivers/net/r8169.c

@@ -2495,7 +2495,7 @@ static inline int rtl8169_try_rx_copy(struct sk_buff **sk_buff, int pkt_size,
 		skb = dev_alloc_skb(pkt_size + align);
 		if (skb) {
 			skb_reserve(skb, (align - 1) & (unsigned long)skb->data);
-			eth_copy_and_sum(skb, sk_buff[0]->data, pkt_size, 0);
+			skb_copy_from_linear_data(*sk_buff, skb->data, pkt_size);
 			*sk_buff = skb;
 			rtl8169_mark_to_asic(desc, rx_buf_sz);
 			ret = 0;