net/mlx5e: Fix warn print in case of TX reporter creation failure

Print warning message in case of TX reporter creation failure, only if the
return value is ERR_PTR type. NULL pointer return indicates that
NET_DEVLINK is not set, and the warning print can be skipped.

Fixes: de8650a8 ("net/mlx5e: Add tx reporter support")
Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

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

@@ -281,7 +281,7 @@ int mlx5e_tx_reporter_create(struct mlx5e_priv *priv)
 		devlink_health_reporter_create(devlink, &mlx5_tx_reporter_ops,
 					       MLX5_REPORTER_TX_GRACEFUL_PERIOD,
 					       true, priv);
-	if (IS_ERR_OR_NULL(priv->tx_reporter))
+	if (IS_ERR(priv->tx_reporter))
 		netdev_warn(priv->netdev,
 			    "Failed to create tx reporter, err = %ld\n",
 			    PTR_ERR(priv->tx_reporter));