Sub: GCS_MAVLink uses compass singleton, stop implementing get_compass

ArduSub/GCS_Mavlink.cpp

@@ -1254,11 +1254,6 @@ void Sub::gcs_update()
     gcs().update();
 }
 
-Compass *GCS_MAVLINK_Sub::get_compass() const
-{
-    return &sub.compass;
-}
-
 AP_Mission *GCS_MAVLINK_Sub::get_mission()
 {
     return &sub.mission;

ArduSub/GCS_Mavlink.h

@@ -12,7 +12,6 @@ protected:
         return 0;
     };
 
-    Compass *get_compass() const override;
     AP_Mission *get_mission() override;
     AP_Rally *get_rally() const override;
     AP_Camera *get_camera() const override;