Copter: use zero_throttle_and_relax_ac in poshold, drift and autotune

ArduCopter/mode_autotune.cpp

@@ -328,8 +328,7 @@ void Copter::ModeAutoTune::run()
     // if not auto armed or motor interlock not enabled set throttle to zero and exit immediately
     // this should not actually be possible because of the init() checks
     if (!motors->armed() || !ap.auto_armed || !motors->get_interlock()) {
-        motors->set_desired_spool_state(AP_Motors::DESIRED_SPIN_WHEN_ARMED);
-        attitude_control->set_throttle_out_unstabilized(0,true,g.throttle_filt);
+        zero_throttle_and_relax_ac();
         pos_control->relax_alt_hold_controllers(0.0f);
         return;
     }

ArduCopter/mode_drift.cpp

@@ -48,8 +48,7 @@ void Copter::ModeDrift::run()
 
     // if landed and throttle at zero, set throttle to zero and exit immediately
     if (!motors->armed() || !motors->get_interlock() || (ap.land_complete && ap.throttle_zero)) {
-        motors->set_desired_spool_state(AP_Motors::DESIRED_SPIN_WHEN_ARMED);
-        attitude_control->set_throttle_out_unstabilized(0,true,g.throttle_filt);
+        zero_throttle_and_relax_ac();
         return;
     }
 

ArduCopter/mode_poshold.cpp

@@ -140,9 +140,8 @@ void Copter::ModePosHold::run()
 
     // if not auto armed or motor interlock not enabled set throttle to zero and exit immediately
     if (!motors->armed() || !ap.auto_armed || !motors->get_interlock()) {
-        motors->set_desired_spool_state(AP_Motors::DESIRED_SPIN_WHEN_ARMED);
         wp_nav->init_loiter_target();
-        attitude_control->set_throttle_out_unstabilized(0,true,g.throttle_filt);
+        zero_throttle_and_relax_ac();
         pos_control->relax_alt_hold_controllers(0.0f);
         return;
     }