Sub: Fix rangefinder init

ArduSub/Sub.h

@@ -178,7 +178,7 @@ private:
     Compass compass;
     AP_InertialSensor ins;
 
-    RangeFinder rangefinder{serial_manager, ROTATION_PITCH_270};
+    RangeFinder rangefinder{serial_manager};
     struct {
         bool enabled:1;
         bool alt_healthy:1; // true if we can trust the altitude from the rangefinder

ArduSub/sensors.cpp

@@ -13,7 +13,7 @@ void Sub::read_barometer()
 void Sub::init_rangefinder()
 {
 #if RANGEFINDER_ENABLED == ENABLED
-    rangefinder.init();
+    rangefinder.init(ROTATION_PITCH_270);
     rangefinder_state.alt_cm_filt.set_cutoff_frequency(RANGEFINDER_WPNAV_FILT_HZ);
     rangefinder_state.enabled = rangefinder.has_orientation(ROTATION_PITCH_270);
 #endif