iwlwifi: fix current channel is not scanned

All channels should be scanned, including the current channel
when the client is associated.

Removed also unused flag to scan only active channels.

Signed-off-by: Guy Cohen <guy.cohen@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>