net/mlx5e: CT: Fix insert rules when TC_CT config isn't enabled

If CONFIG_MLX5_TC_CT isn't enabled, all offloading of eswitch tc rules
fails on parsing ct match, even if there is no ct match.

Return success if there is no ct match, regardless of config.

Fixes: 4c3844d9 ("net/mlx5e: CT: Introduce connection tracking")
Signed-off-by: Paul Blakey <paulb@mellanox.com>
Reviewed-by: Oz Shlomo <ozsh@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.h

@@ -8,6 +8,8 @@
 #include <linux/mlx5/fs.h>
 #include <net/tc_act/tc_ct.h>
 
+#include "en.h"
+
 struct mlx5_esw_flow_attr;
 struct mlx5e_tc_mod_hdr_acts;
 struct mlx5_rep_uplink_priv;
@@ -128,6 +130,11 @@ mlx5_tc_ct_parse_match(struct mlx5e_priv *priv,
 		       struct flow_cls_offload *f,
 		       struct netlink_ext_ack *extack)
 {
+	if (!flow_rule_match_key(f->rule, FLOW_DISSECTOR_KEY_CT))
+		return 0;
+
+	NL_SET_ERR_MSG_MOD(extack, "mlx5 tc ct offload isn't enabled.");
+	netdev_warn(priv->netdev, "mlx5 tc ct offload isn't enabled.\n");
 	return -EOPNOTSUPP;
 }
 
@@ -137,6 +144,8 @@ mlx5_tc_ct_parse_action(struct mlx5e_priv *priv,
 			const struct flow_action_entry *act,
 			struct netlink_ext_ack *extack)
 {
+	NL_SET_ERR_MSG_MOD(extack, "mlx5 tc ct offload isn't enabled.");
+	netdev_warn(priv->netdev, "mlx5 tc ct offload isn't enabled.\n");
 	return -EOPNOTSUPP;
 }