[IPV6]: Kill export of fl6_sock_lookup.

There is no usage of this EXPORT_SYMBOL in the kernel.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/ipv6_syms.c

@@ -37,5 +37,4 @@ EXPORT_SYMBOL(in6_dev_finish_destroy);
 EXPORT_SYMBOL(xfrm6_rcv);
 #endif
 EXPORT_SYMBOL(rt6_lookup);
-EXPORT_SYMBOL(fl6_sock_lookup);
 EXPORT_SYMBOL(ipv6_push_nfrag_opts);