wifi: mac80211: fix CSA processing while scanning

The channel switch parsing code would simply return if a scan is
in-progress. Supposedly, this was because channel switch announcements
from other APs should be ignored.

For the beacon case, the function is already only called if we are
associated with the sender. For the action frame cases, add the
appropriate check whether the frame is coming from the AP we are
associated with. Finally, drop the scanning check from
ieee80211_sta_process_chanswitch.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230608163202.3366e9302468.I6c7e0b58c33b7fb4c675374cfe8c3a5cddcec416@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>