ethernet: ec_bhf: use eth_hw_addr_set()

ethernet: ec_bhf: use eth_hw_addr_set()

Commit 0e59850f1b49 ("net-next: When a bond have a massive amount
of VLANs...") introduced a rbtree for faster Ethernet address look
up. To maintain netdev->dev_addr in this tree we need to make all
the writes to it got through appropriate helpers.

Copy the address into an array on the stack, then call
eth_hw_addr_set().

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>