Copter: change to Compass::learn_offsets

ArduCopter/ArduCopter.pde

@@ -1066,7 +1066,7 @@ static void update_batt_compass(void)
         // update compass with throttle value - used for compassmot
         compass.set_throttle((float)g.rc_3.servo_out/1000.0f);
         if (compass.read()) {
-            compass.null_offsets();
+            compass.learn_offsets();
         }
         // log compass information
         if (g.log_bitmask & MASK_LOG_COMPASS) {

ArduCopter/test.pde

@@ -136,7 +136,7 @@ test_compass(uint8_t argc, const Menu::arg *argv)
                     // Calculate heading
                     const Matrix3f &m = ahrs.get_dcm_matrix();
                     heading = compass.calculate_heading(m);
-                    compass.null_offsets();
+                    compass.learn_offsets();
                 }
                 medium_loopCounter = 0;
             }