[PATCH] netfilter: ipv6: Fix undefined symbol nf_ct_frag6_gather

[wenxu]

From: wenxu <we...@ucloud.cn>

CONFIG_NETFILTER=m and CONFIG_NF_DEFRAG_IPV6 is not set

ERROR: "nf_ct_frag6_gather" [net/ipv6/ipv6.ko] undefined!

Fixes: c9bb6165a16e ("netfilter: nf_conntrack_bridge: fix CONFIG_IPV6=y")
Reported-by: kbuild test robot <l...@intel.com>
Signed-off-by: wenxu <we...@ucloud.cn>
---
 net/ipv6/netfilter.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/ipv6/netfilter.c b/net/ipv6/netfilter.c
index 9530cc2..96d7abf 100644
--- a/net/ipv6/netfilter.c
+++ b/net/ipv6/netfilter.c
@@ -238,8 +238,10 @@ int br_ip6_fragment(struct net *net, struct sock *sk, 
struct sk_buff *skb,
        .route_input            = ip6_route_input,
        .fragment               = ip6_fragment,
        .reroute                = nf_ip6_reroute,
-#if IS_MODULE(CONFIG_IPV6)
+#if IS_MODULE(CONFIG_IPV6) && IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
        .br_defrag              = nf_ct_frag6_gather,
+#endif
+#if IS_MODULE(CONFIG_IPV6)
        .br_fragment            = br_ip6_fragment,
 #endif
 };
-- 
1.8.3.1