DataFlash: Log airspeed.Use

libraries/DataFlash/LogFile.cpp

@@ -1786,7 +1786,8 @@ void DataFlash_Class::Log_Write_Airspeed(AP_Airspeed &airspeed)
         diffpressure  : airspeed.get_differential_pressure(),
         temperature   : (int16_t)(temperature * 100.0f),
         rawpressure   : airspeed.get_raw_pressure(),
-        offset        : airspeed.get_offset()
+        offset        : airspeed.get_offset(),
+        use           : airspeed.use()
     };
     WriteBlock(&pkt, sizeof(pkt));
 }

libraries/DataFlash/LogStructure.h

@@ -577,6 +577,7 @@ struct PACKED log_AIRSPEED {
     int16_t temperature;
     float   rawpressure;
     float   offset;
+    bool    use;
 };
 
 struct PACKED log_ACCEL {
@@ -747,7 +748,7 @@ Format characters in the format string for binary log messages
     { LOG_TRIGGER_MSG, sizeof(log_Camera), \
       "TRIG", "QIHLLeeeccC","TimeUS,GPSTime,GPSWeek,Lat,Lng,Alt,RelAlt,GPSAlt,Roll,Pitch,Yaw" }, \
     { LOG_ARSP_MSG, sizeof(log_AIRSPEED), \
-      "ARSP",  "Qffcff",   "TimeUS,Airspeed,DiffPress,Temp,RawPress,Offset" }, \
+      "ARSP",  "QffcffB",  "TimeUS,Airspeed,DiffPress,Temp,RawPress,Offset,U" }, \
     { LOG_CURRENT_MSG, sizeof(log_Current), \
       "CURR", "QhhhHfh","TimeUS,Throttle,Volt,Curr,Vcc,CurrTot,Volt2" },\
 	{ LOG_ATTITUDE_MSG, sizeof(log_Attitude),\