packet_diag: disclose uid value

This value is disclosed via /proc/net/packet but not via netlink messages.
The goal is to have the same level of information.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/uapi/linux/packet_diag.h b/include/uapi/linux/packet_diag.h
index afafd70..84f83a4 100644
--- a/include/uapi/linux/packet_diag.h
+++ b/include/uapi/linux/packet_diag.h
@@ -32,6 +32,7 @@
 	PACKET_DIAG_RX_RING,
 	PACKET_DIAG_TX_RING,
 	PACKET_DIAG_FANOUT,
+	PACKET_DIAG_UID,
 
 	__PACKET_DIAG_MAX,
 };