net/ncsi: use dev_set_mac_address() for Get MC MAC Address handling

Copy of the rationale from 79007134:

Change ndo_set_mac_address to dev_set_mac_address because
dev_set_mac_address provides a way to notify network layer about MAC
change. In other case, services may not aware about MAC change and keep
using old one which set from network adapter driver.

As example, DHCP client from systemd do not update MAC address without
notification from net subsystem which leads to the problem with acquiring
the right address from DHCP server.

Since dev_set_mac_address requires RTNL lock the operation can not be
performed directly in the response handler, see
9e2bbab9.

The way of selecting the first suitable MAC address from the list is
changed, instead of having the driver check it this patch just assumes
any valid MAC should be good.

Fixes: b8291cf3 ("net/ncsi: Add NC-SI 1.2 Get MC MAC Address command")
Signed-off-by: Paul Fertser <fercerpav@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>