gtp: drop unnecessary call to skb_dst_drop

The call to skb_dst_drop() is already done as part of udp_tunnel_xmit().
Signed-off-by: Jonas Bonn <jonas@norrbonn.se>
Acked-by: Harald Welte <laforge@gnumonks.org>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/gtp.c

@@ -515,8 +515,6 @@ static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev,
 		goto err_rt;
 	}
 
-	skb_dst_drop(skb);
-
 	/* This is similar to tnl_update_pmtu(). */
 	df = iph->frag_off;
 	if (df) {