[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/ipv4/devinet.c b/net/ipv4/devinet.c
index 0487677..8e8d1f1 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -85,7 +85,7 @@
 	[IFA_ADDRESS]   	= { .type = NLA_U32 },
 	[IFA_BROADCAST] 	= { .type = NLA_U32 },
 	[IFA_ANYCAST]   	= { .type = NLA_U32 },
-	[IFA_LABEL]     	= { .type = NLA_STRING },
+	[IFA_LABEL]     	= { .type = NLA_STRING, .len = IFNAMSIZ - 1 },
 };
 
 static void rtmsg_ifa(int event, struct in_ifaddr *, struct nlmsghdr *, u32);