mac80211: always unblock CSA queue stop when disconnecting

In some cases when disconnecting after (or during?) CSA
the queues might not recover, and then the only way to
recover is reloading the module.

Fix this by always unblocking the queue CSA reason when
disconnecting.

Cc: stable@vger.kernel.org
Reported-by: Jan-Michael Brummer <jan.brummer@tabos.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>