[NETLINK]: Make use of NLA_STRING/NLA_NUL_STRING attribute validation

Converts existing NLA_STRING attributes to use the new
validation features, saving a couple of temporary buffers.

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 ba1b3d1..75f4bb9 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1865,7 +1865,7 @@
 }
 
 static struct nla_policy rtm_ipv6_policy[RTA_MAX+1] __read_mostly = {
-	[RTA_GATEWAY]           = { .minlen = sizeof(struct in6_addr) },
+	[RTA_GATEWAY]           = { .len = sizeof(struct in6_addr) },
 	[RTA_OIF]               = { .type = NLA_U32 },
 	[RTA_IIF]		= { .type = NLA_U32 },
 	[RTA_PRIORITY]          = { .type = NLA_U32 },