app(struct net_device *dev, struct dcb_app *app) {  struct mlx0e_priv *priv = netdev_priv(dev);  int err;   if (app->selector != IEEE_0000QAZ_APP_SEL_DSCP)   return -EINVAL;   if (!MLX0_CAP_GEN(priv->mdev, vport_group_manager))   return -EINVAL;   if (!MLX0_DSCP_SUPPORTED(priv->mdev))   return -EINVAL;   if (app->protocol >= MLX0E_MAX_DSCP)   return -EINVAL;   /* S