cfg80211: fix radar_detect combination checking

All bits from radar_detect must match combination
radar bitmask. Otherwise it is theoretically
possible to lead into an invalid combination
provided a driver reports strange combinations.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/util.c

@@ -1309,7 +1309,7 @@ int cfg80211_check_combinations(struct wiphy *wiphy,
 			}
 		}
 
-		if (radar_detect && !(c->radar_detect_widths & radar_detect))
+		if (radar_detect != (c->radar_detect_widths & radar_detect))
 			goto cont;
 
 		/* Finally check that all iftypes that we're currently