Plane: let GCS_MAVLink calibrate airspeed sensor

Also remove useless zero_airspeed function

ArduPlane/GCS_Mavlink.cpp

@@ -849,20 +849,6 @@ MAV_RESULT GCS_MAVLINK_Plane::handle_command_preflight_calibration(const mavlink
     return ret;
 }
 
-MAV_RESULT GCS_MAVLINK_Plane::_handle_command_preflight_calibration_baro()
-{
-    /*
-      baro and airspeed calibration
-    */
-    MAV_RESULT ret = GCS_MAVLINK::_handle_command_preflight_calibration_baro();
-    if (ret == MAV_RESULT_ACCEPTED) {
-        if (plane.airspeed.enabled()) {
-            plane.zero_airspeed(false);
-        }
-    }
-    return ret;
-}
-
 MAV_RESULT GCS_MAVLINK_Plane::_handle_command_preflight_calibration(const mavlink_command_long_t &packet)
 {
     if (is_equal(packet.param4,1.0f)) {

ArduPlane/GCS_Mavlink.h

@@ -33,7 +33,6 @@ protected:
 
     bool set_mode(uint8_t mode) override;
 
-    MAV_RESULT _handle_command_preflight_calibration_baro() override;
     MAV_RESULT handle_command_preflight_calibration(const mavlink_command_long_t &packet) override;
     MAV_RESULT _handle_command_preflight_calibration(const mavlink_command_long_t &packet) override;
 

ArduPlane/Plane.h

@@ -929,7 +929,6 @@ private:
     void init_rangefinder(void);
     void read_rangefinder(void);
     void read_airspeed(void);
-    void zero_airspeed(bool in_startup);
     void read_receiver_rssi(void);
     void rpm_update(void);
     void button_update(void);

ArduPlane/sensors.cpp

@@ -96,15 +96,6 @@ void Plane::read_airspeed(void)
     }
 }
 
-void Plane::zero_airspeed(bool in_startup)
-{
-    airspeed.calibrate(in_startup);
-    read_airspeed();
-    // update barometric calibration with new airspeed supplied temperature
-    barometer.update_calibration();
-    gcs().send_text(MAV_SEVERITY_INFO,"Airspeed calibration started");
-}
-
 // read the receiver RSSI as an 8 bit number for MAVLink
 // RC_CHANNELS_SCALED message
 void Plane::read_receiver_rssi(void)

ArduPlane/system.cpp

@@ -592,7 +592,7 @@ void Plane::startup_INS_ground(void)
     if (airspeed.enabled()) {
         // initialize airspeed sensor
         // --------------------------
-        zero_airspeed(true);
+        airspeed.calibrate(true);
     } else {
         gcs().send_text(MAV_SEVERITY_WARNING,"No airspeed");
     }