[NETLINK]: Introduce nested and byteorder flag to netlink attribute

This change allows the generic attribute interface to be used within
the netfilter subsystem where this flag was initially introduced.

The byte-order flag is yet unused, it's intended use is to
allow automatic byte order convertions for all atomic types.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 5bdd9d4..104070e 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1279,7 +1279,7 @@
 		int remaining;
 
 		nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) {
-			int type = nla->nla_type;
+			int type = nla_type(nla);
 
 			if (type) {
 				if (type > RTAX_MAX) {