Rover: always specify rangefinder instance

APMrover2/Rover.h

@@ -142,7 +142,7 @@ private:
     AP_Baro barometer;
     Compass compass;
     AP_InertialSensor ins;
-    RangeFinder sonar { serial_manager };
+    RangeFinder sonar { serial_manager, ROTATION_NONE };
     AP_Button button;
 
     // flight modes convenience array

APMrover2/sensors.cpp

@@ -56,7 +56,7 @@ void Rover::read_sonars(void)
 {
     sonar.update();
 
-    if (sonar.status() == RangeFinder::RangeFinder_NotConnected) {
+    if (sonar.status(0) == RangeFinder::RangeFinder_NotConnected) {
         // this makes it possible to disable sonar at runtime
         return;
     }
@@ -214,7 +214,7 @@ void Rover::update_sensor_status_flags(void)
         if (g.sonar_trigger_cm > 0) {
             control_sensors_enabled |= MAV_SYS_STATUS_SENSOR_LASER_POSITION;
         }
-        if (sonar.has_data()) {
+        if (sonar.has_data(0)) {
             control_sensors_health |= MAV_SYS_STATUS_SENSOR_LASER_POSITION;
         }
     }

APMrover2/test.cpp

@@ -365,7 +365,7 @@ int8_t Rover::test_sonar(uint8_t argc, const Menu::arg *argv)
     delay(20);
     sonar.update();
 
-    if (sonar.status() == RangeFinder::RangeFinder_NotConnected) {
+    if (sonar.status(0) == RangeFinder::RangeFinder_NotConnected && sonar.status(1) == RangeFinder::RangeFinder_NotConnected) {
         cliSerial->printf("WARNING: Sonar is not enabled\n");
     }