ArduPlane: use mission singleton inside AP_AdvancedFailsafe

ArduPlane/Plane.h

@@ -644,7 +644,7 @@ private:
 
     // Outback Challenge Failsafe Support
 #if ADVANCED_FAILSAFE == ENABLED
-    AP_AdvancedFailsafe_Plane afs {mission};
+    AP_AdvancedFailsafe_Plane afs;
 #endif
 
     /*

ArduPlane/afs_plane.cpp

@@ -5,11 +5,6 @@
 #include "Plane.h"
 
 #if ADVANCED_FAILSAFE == ENABLED
-// Constructor
-AP_AdvancedFailsafe_Plane::AP_AdvancedFailsafe_Plane(AP_Mission &_mission) :
-    AP_AdvancedFailsafe(_mission)
-{}
-
 
 /*
   setup radio_out values for all channels to termination values

ArduPlane/afs_plane.h

@@ -27,7 +27,8 @@
 class AP_AdvancedFailsafe_Plane : public AP_AdvancedFailsafe
 {
 public:
-    AP_AdvancedFailsafe_Plane(AP_Mission &_mission);
+
+    using AP_AdvancedFailsafe::AP_AdvancedFailsafe;
 
     // called to set all outputs to termination state
     void terminate_vehicle(void) override;