iwl3945: remove STATUS macros from header

iwl3945 includes iwl-core.h in which these STATUS flags are already
defined. This also removes a potential confusing definition with iwlcore
using STATUS_MODE_PENDING with value 18 and iwl3945 defining (but not
using) STATUS_CONF_PENDING for value 18.

Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>