FW bug in checking if landing point has been passed

* the bearing difference between the waypoints and aircraft to landing point should be wrap_pi'ed

src/modules/fw_pos_control_l1/FixedwingPositionControl.hpp

@@ -97,6 +97,7 @@ using matrix::Eulerf;
 using matrix::Quatf;
 using matrix::Vector2f;
 using matrix::Vector3f;
+using matrix::wrap_pi;
 
 using uORB::Subscription;