[IPV6]: Clean up duplicate includes in net/ipv6/

This patch cleans up duplicate includes in
	net/ipv6/

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/tcp_ipv6.c

@@ -56,7 +56,6 @@
 #include <net/inet_ecn.h>
 #include <net/protocol.h>
 #include <net/xfrm.h>
-#include <net/addrconf.h>
 #include <net/snmp.h>
 #include <net/dsfield.h>
 #include <net/timewait_sock.h>