[skip ci] Var rename

include/laser/state_block/state_polyline_point_2d.h

@@ -9,9 +9,9 @@ class StatePolylinePoint2d : public StatePoint2d
 {
   public:
     StatePolylinePoint2d(const Vector2d &_point,
-                         StateBlockPtr   _adjacent      = nullptr,
-                         bool            _fixed         = false,
-                         bool            _transformable = true);
+                         StateBlockPtr   _reference_point = nullptr,
+                         bool            _fixed           = false,
+                         bool            _transformable   = true);
 
     ~StatePolylinePoint2d() {}
 };