[PATCH] iwl3945: fix direct scan problem

This patch fix the follwing for 3945:
1. Fix direct scan by make sure we set one_direct_scan only when the
   mac80211 ask for direct scan.
2. Fix mac_stop and mac_remove_interface calles, we make sure we cancel any
   scan and disassoc on these call

Signed-off-by: Mohamed Abbas <mabbas@linux.intel.com>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>