ucc_geth: fix module removal

- uccf should be set to NULL to not double-free memory on
  subsequent calls;
- ind_hash_q and group_hash_q lists should be initialized in the
  probe() function, instead of struct_init() (called by open()),
  otherwise there will be an oops if ucc_geth_driver removed
  prior 'ifconfig ethX up';
- add unregister_netdev();
- reorder geth_remove() steps.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: David S. Miller <davem@davemloft.net>