net/mlx5e: Fix error path of device attach

On failure to attach the netdev, fix the rollback by re-setting the
device's state back to MLX5E_STATE_DESTROYING.

Failing to attach doesn't stop statistics polling via .ndo_get_stats64.
In this case, although the device is not attached, it falsely continues
to query the firmware for counters. Setting the device's state back to
MLX5E_STATE_DESTROYING prevents the firmware counters query.

Fixes: 26e59d8 ("net/mlx5e: Implement mlx5e interface attach/detach callbacks")
Signed-off-by: Aya Levin <ayal@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

drivers/net/ethernet/mellanox/mlx5/core/en_main.c

@@ -5390,6 +5390,8 @@ int mlx5e_attach_netdev(struct mlx5e_priv *priv)
 	profile->cleanup_tx(priv);
 
 out:
+	set_bit(MLX5E_STATE_DESTROYING, &priv->state);
+	cancel_work_sync(&priv->update_stats_work);
 	return err;
 }