net/mlx4_core: Fix to clean devlink resources

This patch cleans devlink resources by calling devlink_port_unregister()
to avoid the following issues:

- Kernel panic when triggering reset flow.
- Memory leak due to unfreed resources in mlx4_init_port_info().

Fixes: 09d4d087cd48 ("mlx4: Implement devlink interface")
Signed-off-by: Kamal Heib <kamalh@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -2970,6 +2970,7 @@ static int mlx4_init_port_info(struct mlx4_dev *dev, int port)
 		mlx4_err(dev, "Failed to create mtu file for port %d\n", port);
 		device_remove_file(&info->dev->persist->pdev->dev,
 				   &info->port_attr);
+		devlink_port_unregister(&info->devlink_port);
 		info->port = -1;
 	}
 
@@ -2984,6 +2985,8 @@ static void mlx4_cleanup_port_info(struct mlx4_port_info *info)
 	device_remove_file(&info->dev->persist->pdev->dev, &info->port_attr);
 	device_remove_file(&info->dev->persist->pdev->dev,
 			   &info->port_mtu_attr);
+	devlink_port_unregister(&info->devlink_port);
+
 #ifdef CONFIG_RFS_ACCEL
 	free_irq_cpu_rmap(info->rmap);
 	info->rmap = NULL;