Tracker: use baro singleton

AntennaTracker/GCS_Mavlink.cpp

@@ -202,12 +202,12 @@ bool GCS_MAVLINK_Tracker::try_send_message(enum ap_message id)
 
     case MSG_RAW_IMU2:
         CHECK_PAYLOAD_SIZE(SCALED_PRESSURE);
-        send_scaled_pressure(tracker.barometer);
+        send_scaled_pressure();
         break;
 
     case MSG_RAW_IMU3:
         CHECK_PAYLOAD_SIZE(SENSOR_OFFSETS);
-        send_sensor_offsets(tracker.ins, tracker.compass, tracker.barometer);
+        send_sensor_offsets(tracker.ins, tracker.compass);
         break;
 
     case MSG_SIMSTATE:

AntennaTracker/Log.cpp

@@ -21,7 +21,7 @@ void Tracker::Log_Write_Attitude()
 
 void Tracker::Log_Write_Baro(void)
 {
-    DataFlash.Log_Write_Baro(barometer);
+    DataFlash.Log_Write_Baro();
 }
 
 struct PACKED log_Vehicle_Baro {

AntennaTracker/Tracker.h

@@ -116,11 +116,11 @@ private:
 
 // Inertial Navigation EKF
 #if AP_AHRS_NAVEKF_AVAILABLE
-    NavEKF2 EKF2{&ahrs, barometer, rng};
-    NavEKF3 EKF3{&ahrs, barometer, rng};
-    AP_AHRS_NavEKF ahrs{ins, barometer, EKF2, EKF3};
+    NavEKF2 EKF2{&ahrs, rng};
+    NavEKF3 EKF3{&ahrs, rng};
+    AP_AHRS_NavEKF ahrs{ins, EKF2, EKF3};
 #else
-    AP_AHRS_DCM ahrs{ins, barometer};
+    AP_AHRS_DCM ahrs{ins};
 #endif
 
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL