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: 48189d6a ("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>