net/mlx4_en: Fix resource leak in error flow

Wrong condition was used when calling iounmap.
Signed-off-by: NDotan Barak <dotanb@dev.mellanox.com>
Signed-off-by: NAmir Vadai <amirv@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx4/en_main.c

@@ -310,7 +310,7 @@ static void *mlx4_en_add(struct mlx4_dev *dev)
 err_mr:
 	(void) mlx4_mr_free(dev, &mdev->mr);
 err_map:
-	if (!mdev->uar_map)
+	if (mdev->uar_map)
 		iounmap(mdev->uar_map);
 err_uar:
 	mlx4_uar_free(dev, &mdev->priv_uar);