net/mlx5: DR, Fix uninitialized var warning

Smatch warns this:

drivers/net/ethernet/mellanox/mlx5/core/steering/dr_table.c:81
 mlx5dr_table_set_miss_action() error: uninitialized symbol 'ret'.

Initializing ret with -EOPNOTSUPP and fix missing action case.

Fixes: 7838e172 ("net/mlx5: DR, Expose steering table functionality")
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Reviewed-by: NRoi Dayan <roid@nvidia.com>
Signed-off-by: NSaeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/steering/dr_table.c

@@ -46,7 +46,7 @@ static int dr_table_set_miss_action_nic(struct mlx5dr_domain *dmn,
 int mlx5dr_table_set_miss_action(struct mlx5dr_table *tbl,
 				 struct mlx5dr_action *action)
 {
-	int ret;
+	int ret = -EOPNOTSUPP;
 
 	if (action && action->action_type != DR_ACTION_TYP_FT)
 		return -EOPNOTSUPP;
@@ -67,6 +67,9 @@ int mlx5dr_table_set_miss_action(struct mlx5dr_table *tbl,
 			goto out;
 	}
 
+	if (ret)
+		goto out;
+
 	/* Release old action */
 	if (tbl->miss_action)
 		refcount_dec(&tbl->miss_action->refcount);