rt2x00: Mark active channel's survey data as "in use"

This is just a cosmetical fix since we only return survey data for the
active channel but it allows iw to show that the survey data is
for the currently used channel.

Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/rt2x00/rt2800lib.c

@@ -4554,6 +4554,9 @@ int rt2800_get_survey(struct ieee80211_hw *hw, int idx,
 		survey->channel_time_ext_busy = busy_ext / 1000;
 	}
 
+	if (!(hw->conf.flags & IEEE80211_CONF_OFFCHANNEL))
+		survey->filled |= SURVEY_INFO_IN_USE;
+
 	return 0;
 
 }