r8169: fix kasan reported skb use-after-free.

Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Fixes: d7d2d89d4b0af ("r8169: Add software counter for multicast packages")
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Corinna Vinschen <vinschen@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/realtek/r8169.c

@@ -7429,15 +7429,15 @@ static int rtl_rx(struct net_device *dev, struct rtl8169_private *tp, u32 budget
 
 			rtl8169_rx_vlan_tag(desc, skb);
 
+			if (skb->pkt_type == PACKET_MULTICAST)
+				dev->stats.multicast++;
+
 			napi_gro_receive(&tp->napi, skb);
 
 			u64_stats_update_begin(&tp->rx_stats.syncp);
 			tp->rx_stats.packets++;
 			tp->rx_stats.bytes += pkt_size;
 			u64_stats_update_end(&tp->rx_stats.syncp);
-
-			if (skb->pkt_type == PACKET_MULTICAST)
-				dev->stats.multicast++;
 		}
 release_descriptor:
 		desc->opts2 = 0;