iwl3945: Fix iwl3945_init_drv()

iwl3945_init_drv() initialises the wrong lock, and sets the wrong power saving
default level.
With this power saving mode, we are losing a lot of frames in Ad-Hoc mode.

This is a bug fix for bug #1873.
( http://www.intellinuxwireless.org/bugzilla/show_bug.cgi?id=1873 )

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