AP_ADSB: use AP::ahrs() singleton

libraries/AP_ADSB/AP_ADSB.cpp

@@ -161,7 +161,7 @@ void AP_ADSB::deinit(void)
 void AP_ADSB::update(void)
 {
     // update _my_loc
-    if (!_ahrs.get_position(_my_loc)) {
+    if (!AP::ahrs().get_position(_my_loc)) {
         _my_loc.zero();
     }
 
@@ -506,7 +506,7 @@ void AP_ADSB::send_dynamic_out(const mavlink_channel_t chan)
     const uint64_t gps_time = gps.time_epoch_usec();
     const uint32_t utcTime = gps_time / 1000000ULL;
 
-    const AP_Baro &baro = _ahrs.get_baro();
+    const AP_Baro &baro = AP::ahrs().get_baro();
     int32_t altPres = INT_MAX;
     if (baro.healthy()) {
         // Altitude difference between 101325 (Pascals) and current pressure. Result in millimeters

libraries/AP_ADSB/AP_ADSB.h

@@ -31,8 +31,7 @@
 
 class AP_ADSB {
 public:
-    AP_ADSB(const AP_AHRS &ahrs)
-        : _ahrs(ahrs)
+    AP_ADSB()
     {
         AP_Param::setup_object_defaults(this, var_info);
     }
@@ -109,10 +108,6 @@ private:
     // handle ADS-B transceiver report for ping2020
     void handle_transceiver_report(mavlink_channel_t chan, const mavlink_message_t* msg);
 
-    // reference to AHRS, so we can ask for our position,
-    // heading and speed
-    const AP_AHRS &_ahrs;
-
     AP_Int8     _enabled;
 
     Location_Class  _my_loc;