cfg80211/mac80211/ath6kl: acquire wdev lock outside ch_switch_notify

The channel switch notification should be sent under the
wdev/sdata-lock, preferably in the same moment as the channel change
happens, to avoid races by other callers (e.g. start/stop_ap).
This also adds the previously missing sdata_lock protection in
csa_finalize_work.

Reported-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 6c2bc32..e9abc7b 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -4286,7 +4286,8 @@
  * @dev: the device which switched channels
  * @chandef: the new channel definition
  *
- * Acquires wdev_lock, so must only be called from sleepable driver context!
+ * Caller must acquire wdev_lock, therefore must only be called from sleepable
+ * driver context!
  */
 void cfg80211_ch_switch_notify(struct net_device *dev,
 			       struct cfg80211_chan_def *chandef);