Plane: rename update_throttle_mix

was called update_throttle_thr_mix
also minor format fixes

ArduPlane/ArduPlane.cpp

@@ -177,7 +177,7 @@ void Plane::update_speed_height(void)
 
     if (quadplane.in_vtol_mode() ||
         quadplane.in_assisted_flight()) {
-        quadplane.update_throttle_thr_mix();
+        quadplane.update_throttle_mix();
     }
 }
 

ArduPlane/quadplane.cpp

@@ -3150,7 +3150,7 @@ float QuadPlane::stopping_distance(void)
 #define LAND_CHECK_LARGE_ANGLE_CD   1500.0f     // maximum angle target to be considered landing
 #define LAND_CHECK_ACCEL_MOVING     3.0f        // maximum acceleration after subtracting gravity
 
-void QuadPlane::update_throttle_thr_mix(void)
+void QuadPlane::update_throttle_mix(void)
 {
     // transition will directly manage the mix
     if (in_transition()) {

ArduPlane/quadplane.h

@@ -53,7 +53,7 @@ public:
     void takeoff_controller(void);
     void waypoint_controller(void);
 
-    void update_throttle_thr_mix(void);
+    void update_throttle_mix(void);
     
     // update transition handling
     void update(void);