r8169: improve DMA handling in rtl_rx

Move the call to dma_sync_single_for_cpu after calling napi_alloc_skb.
This avoids calling dma_sync_single_for_cpu w/o handing control back
to device if the memory allocation should fail.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/realtek/r8169_main.c

@@ -5807,16 +5807,15 @@ static int rtl_rx(struct net_device *dev, struct rtl8169_private *tp, u32 budget
 				goto release_descriptor;
 			}
 
-			dma_sync_single_for_cpu(tp_to_dev(tp),
-						le64_to_cpu(desc->addr),
-						pkt_size, DMA_FROM_DEVICE);
-
 			skb = napi_alloc_skb(&tp->napi, pkt_size);
 			if (unlikely(!skb)) {
 				dev->stats.rx_dropped++;
 				goto release_descriptor;
 			}
 
+			dma_sync_single_for_cpu(tp_to_dev(tp),
+						le64_to_cpu(desc->addr),
+						pkt_size, DMA_FROM_DEVICE);
 			prefetch(rx_buf);
 			skb_copy_to_linear_data(skb, rx_buf, pkt_size);
 			skb->tail += pkt_size;