netfilter: nf_tables: remove NFT_CT_TIMEOUT

Never used anywhere in the code.

Fixes: 7e0b2b57 ("netfilter: nft_ct: add ct timeout support")
Reported-by: Stéphane Veyret <sveyret@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/uapi/linux/netfilter/nf_tables.h

@@ -966,7 +966,6 @@ enum nft_socket_keys {
  * @NFT_CT_DST_IP: conntrack layer 3 protocol destination (IPv4 address)
  * @NFT_CT_SRC_IP6: conntrack layer 3 protocol source (IPv6 address)
  * @NFT_CT_DST_IP6: conntrack layer 3 protocol destination (IPv6 address)
- * @NFT_CT_TIMEOUT: connection tracking timeout policy assigned to conntrack
  */
 enum nft_ct_keys {
 	NFT_CT_STATE,
@@ -992,7 +991,6 @@ enum nft_ct_keys {
 	NFT_CT_DST_IP,
 	NFT_CT_SRC_IP6,
 	NFT_CT_DST_IP6,
-	NFT_CT_TIMEOUT,
 	__NFT_CT_MAX
 };
 #define NFT_CT_MAX		(__NFT_CT_MAX - 1)