Rover: change to Compass::learn_offsets

APMrover2/APMrover2.pde

@@ -710,7 +710,7 @@ static void update_compass(void)
     if (g.compass_enabled && compass.read()) {
         ahrs.set_compass(&compass);
         // update offsets
-        compass.null_offsets();
+        compass.learn_offsets();
         if (should_log(MASK_LOG_COMPASS)) {
             Log_Write_Compass();
         }

APMrover2/test.pde

@@ -410,7 +410,7 @@ test_mag(uint8_t argc, const Menu::arg *argv)
                 // Calculate heading
                 Matrix3f m = ahrs.get_dcm_matrix();
                 heading = compass.calculate_heading(m);
-                compass.null_offsets();
+                compass.learn_offsets();
             }
             medium_loopCounter = 0;
         }