AP_SmartRTL: rangefinder no longer takes SerialManager in constructor

libraries/AP_SmartRTL/examples/SmartRTL_test/SmartRTL_test.cpp

@@ -20,7 +20,7 @@ static AP_SerialManager serial_manager;
 
 class DummyVehicle {
 public:
-    RangeFinder rangefinder{serial_manager};
+    RangeFinder rangefinder;
     NavEKF2 EKF2{&ahrs, rangefinder};
     NavEKF3 EKF3{&ahrs, rangefinder};
     AP_AHRS_NavEKF ahrs{EKF2, EKF3, AP_AHRS_NavEKF::FLAG_ALWAYS_USE_EKF};