Set addr_assign_type correctly to NET_ADDR_RANDOM in case
a random MAC address was generated and assigned to the netdevice.

Fix error handling in atl1c_probe(). If atl1c_read_mac_addr()
couldn't get the hw mac address, and a random mac address get
set return the error code. Don't go to err_eeprom in
atl1c_probe(), use the generated MAC address in this case.

Reset the state to NET_ADDR_PERM as soon as the MAC get
changed via .ndo_set_mac_address.

v2: use bitops
Signed-off-by: NDanny Kukawka <danny.kukawka@bisect.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>