netfilter: xt_socket: fix a typo in socket_mt_destroy()

Calling nf_defrag_ipv4_disable() instead of nf_defrag_ipv6_disable()
was probably not the intent.

I found this by code inspection, while chasing a possible issue in TPROXY.

Fixes: de8c1211 ("netfilter: disable defrag once its no longer needed")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/xt_socket.c

@@ -221,7 +221,7 @@ static void socket_mt_destroy(const struct xt_mtdtor_param *par)
 	if (par->family == NFPROTO_IPV4)
 		nf_defrag_ipv4_disable(par->net);
 	else if (par->family == NFPROTO_IPV6)
-		nf_defrag_ipv4_disable(par->net);
+		nf_defrag_ipv6_disable(par->net);
 }
 
 static struct xt_match socket_mt_reg[] __read_mostly = {