net: hns: fix warning of passing zero to 'PTR_ERR'

There is a misuse of PTR as shown below:

	ae_node = (void *)of_parse_phandle(dev->of_node,
					   "ae-handle",
					   0);
	if (IS_ERR_OR_NULL(ae_node)) {
		ret = PTR_ERR(ae_node);
		dev_err(dev, "not find ae-handle\n");
		goto out_read_prop_fail;
	}

if the ae_node is NULL, PTR_ERR(ae_node) means it returns success. And the
return value should be -ENODEV.

Signed-off-by: Kejian Yan <yankejian@huawei.com>
Signed-off-by: Yisen Zhuang <Yisen.Zhuang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>