net: hns: Fix for missing of_node_put() after of_parse_phandle()

In hns enet driver, we use of_parse_handle() to get hold of the
device node related to "ae-handle" but we have missed to put
the node reference using of_node_put() after we are done using
the node. This patch fixes it.

Note:
This problem is stated in Link: https://lkml.org/lkml/2018/12/22/217

Fixes: 48189d6 ("net: hns: enet specifies a reference to dsaf")
Reported-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Yonglong Liu <liuyonglong@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/hisilicon/hns/hns_enet.c

@@ -2418,6 +2418,8 @@ static int hns_nic_dev_probe(struct platform_device *pdev)
 out_notify_fail:
 	(void)cancel_work_sync(&priv->service_task);
 out_read_prop_fail:
+	/* safe for ACPI FW */
+	of_node_put(to_of_node(priv->fwnode));
 	free_netdev(ndev);
 	return ret;
 }
@@ -2447,6 +2449,9 @@ static int hns_nic_dev_remove(struct platform_device *pdev)
 	set_bit(NIC_STATE_REMOVING, &priv->state);
 	(void)cancel_work_sync(&priv->service_task);
 
+	/* safe for ACPI FW */
+	of_node_put(to_of_node(priv->fwnode));
+
 	free_netdev(ndev);
 	return 0;
 }