usbb: catc: use correct API for MAC addresses

Commit 406f42fa

 ("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.

In the case of catc we need a new temporary buffer to conform
to the rules for DMA coherency. That in turn necessitates
a reworking of error handling in probe().

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>