AC_InputManager: replace header guard with pragma once

libraries/AC_InputManager/AC_InputManager.h

@@ -1,11 +1,9 @@
 // -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
+#pragma once
 
 /// @file   AC_InputManager.h
 /// @brief  Pilot manual control input library
 
-#ifndef AC_INPUTMANAGER_H
-#define AC_INPUTMANAGER_H
-
 #include <AP_Common/AP_Common.h>
 #include <AP_Param/AP_Param.h>
 #include <AP_Math/AP_Math.h>
@@ -29,5 +27,3 @@ protected:
     uint16_t            _loop_rate;             // rate at which output() function is called (normally 400hz)
 
 };
-
-#endif /* AC_INPUTMANAGER_H */

libraries/AC_InputManager/AC_InputManager_Heli.h

@@ -1,11 +1,9 @@
 // -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
+#pragma once
 
 /// @file   AC_InputManager_Heli.h
 /// @brief  Pilot manual control input library for Conventional Helicopter
 
-#ifndef AC_INPUTMANAGER_HELI_H
-#define AC_INPUTMANAGER_HELI_H
-
 #include <AP_Param/AP_Param.h>
 #include <AP_Common/AP_Common.h>
 #include "AC_InputManager.h"
@@ -54,5 +52,3 @@ private:
     AP_Float        _acro_col_expo;                 // used to soften collective pitch inputs near center point in Acro mode
 
 };
-
-#endif /* AC_INPUTMANAGER_HELI_H */