S2IO: Restoring the mac address in s2io_reset

- Restore in s2io_reset, the mac address assigned during s2io_open.
  Earlier, it was getting overwritten to the factory default (read from the
  eeprom) and subsequently dropping received frames.

- Fixed the typo in calling rtnl_unlock in s2io_set_link function.

Signed-off-by: Sivakumar Subramani <sivakumar.subramani@neterion.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>