net/mlx5: Remove unneeded variable in mlx5_unload_one

mlx5_unload_one do not need local variable to store different value,
Hence just remove it.
Signed-off-by: Nzhong jiang <zhongjiang@huawei.com>
Acked-by: NSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

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

@@ -1228,8 +1228,6 @@ static int mlx5_load_one(struct mlx5_core_dev *dev, bool boot)
 
 static int mlx5_unload_one(struct mlx5_core_dev *dev, bool cleanup)
 {
-	int err = 0;
-
 	if (cleanup) {
 		mlx5_unregister_device(dev);
 		mlx5_drain_health_wq(dev);
@@ -1257,7 +1255,7 @@ static int mlx5_unload_one(struct mlx5_core_dev *dev, bool cleanup)
 	mlx5_function_teardown(dev, cleanup);
 out:
 	mutex_unlock(&dev->intf_state_mutex);
-	return err;
+	return 0;
 }
 
 static int mlx5_mdev_init(struct mlx5_core_dev *dev, int profile_idx)