AP_SmartRTL: use ins singleton

libraries/AP_SmartRTL/examples/SmartRTL_test/SmartRTL_test.cpp

@@ -23,7 +23,7 @@ public:
     RangeFinder rangefinder{serial_manager, ROTATION_PITCH_270};
     NavEKF2 EKF2{&ahrs, rangefinder};
     NavEKF3 EKF3{&ahrs, rangefinder};
-    AP_AHRS_NavEKF ahrs{ins, EKF2, EKF3, AP_AHRS_NavEKF::FLAG_ALWAYS_USE_EKF};
+    AP_AHRS_NavEKF ahrs{EKF2, EKF3, AP_AHRS_NavEKF::FLAG_ALWAYS_USE_EKF};
 };
 
 static DummyVehicle vehicle;