mac80211: don't defer scans in case of radar detection

Radar detection can last indefinite time. There is no
point in deferring a scan request in this case - simply
return -EBUSY.

Signed-off-by: Eliad Peller <eliad@wizery.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/scan.c

@@ -505,7 +505,7 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
 
 	lockdep_assert_held(&local->mtx);
 
-	if (local->scan_req)
+	if (local->scan_req || ieee80211_is_radar_required(local))
 		return -EBUSY;
 
 	if (!ieee80211_can_scan(local, sdata)) {