net: ip6_gre: Remove the unused function ip6gre_tnl_addr_conflict()

The function ip6gre_tnl_addr_conflict() is defined in the ip6_gre.c file,
but not called elsewhere, so delete this unused function.

net/ipv6/ip6_gre.c:887:20: warning: unused function 'ip6gre_tnl_addr_conflict'.

Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=2419
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Link: https://lore.kernel.org/r/20221017093540.26806-1-jiapeng.chong@linux.alibaba.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

net/ipv6/ip6_gre.c

@@ -870,26 +870,6 @@ static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
 	return 0;
 }
 
-/**
- * ip6gre_tnl_addr_conflict - compare packet addresses to tunnel's own
- *   @t: the outgoing tunnel device
- *   @hdr: IPv6 header from the incoming packet
- *
- * Description:
- *   Avoid trivial tunneling loop by checking that tunnel exit-point
- *   doesn't match source of incoming packet.
- *
- * Return:
- *   1 if conflict,
- *   0 else
- **/
-
-static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
-	const struct ipv6hdr *hdr)
-{
-	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
-}
-
 static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
 {
 	struct ip6_tnl *t = netdev_priv(dev);