ip6_udp_tunnel: remove unused IPCB related codes

Some IPCB fields are currently set in udp_tunnel6_xmit_skb(), which are
never used before it reaches ip6tunnel_xmit(), and past that point the
control buffer is no longer interpreted as IPCB.

This clears these unused IPCB related codes. Currently there is no skb
scrubbing in ip6_udp_tunnel, otherwise IPCB(skb)->opt might need to be
cleared for IPv4 packets, as shown in 5146d1f1511
("tunnel: Clear IPCB(skb)->opt before dst_link_failure called").

Signed-off-by: Eli Cooper <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/ipv6/ip6_udp_tunnel.c

···
 
 	uh->len = htons(skb->len);
 
-	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
-	IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED
-			    | IPSKB_REROUTED);
 	skb_dst_set(skb, dst);
 
 	udp6_set_csum(nocheck, skb, saddr, daddr, skb->len);