net: hns3: rename the interface for init_client_instance and uninit_client_instance

The interface init_client_instance and uninit_client_instance
do not register anything, only initialize the client instance.
This patch rename the related interface to make the function
name to indicate the purpose.

Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>