ipv6: convert addrconf list to hlist

Using hash list macros, simplifies code and helps later RCU.

This patch includes some initialization that is not strictly necessary,
since an empty hlist node/list is all zero; and list is in BSS
and node is allocated with kzalloc.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h
index 09d9064..4984015 100644
--- a/include/net/if_inet6.h
+++ b/include/net/if_inet6.h
@@ -54,7 +54,7 @@
 	struct inet6_dev	*idev;
 	struct rt6_info		*rt;
 
-	struct inet6_ifaddr	*lst_next;      /* next addr in addr_lst */
+	struct hlist_node	addr_lst;
 	struct inet6_ifaddr	*if_next;       /* next addr in inet6_dev */
 
 #ifdef CONFIG_IPV6_PRIVACY