net/mlx5e: CT: Avoid false warning about rule may be used uninitialized

Avoid gcc warning by preset rule to invalid ptr.

Fixes: 4c3844d9 ("net/mlx5e: CT: Introduce connection tracking")
Signed-off-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

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

@@ -1131,7 +1131,7 @@ mlx5_tc_ct_flow_offload(struct mlx5e_priv *priv,
 {
 	bool clear_action = attr->ct_attr.ct_action & TCA_CT_ACT_CLEAR;
 	struct mlx5_tc_ct_priv *ct_priv = mlx5_tc_ct_get_ct_priv(priv);
-	struct mlx5_flow_handle *rule;
+	struct mlx5_flow_handle *rule = ERR_PTR(-EINVAL);
 	int err;
 
 	if (!ct_priv)