netfilter: nft_ct: add byte/packet counter support

If the accounting extension isn't present, we'll return a counter
value of 0.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
index 03c28a4..be41ffc 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -757,6 +757,8 @@
 	NFT_CT_PROTO_SRC,
 	NFT_CT_PROTO_DST,
 	NFT_CT_LABELS,
+	NFT_CT_PKTS,
+	NFT_CT_BYTES,
 };
 
 /**