acc_diameter: use file specific include guard

(cherry picked from commit 3d73e8cb9f7431383c5a4ce798e2610f37ff92dc)
(cherry picked from commit 83f20f6b0e8a3e4a6c6b5351526f67b63f10da3e)

src/modules/acc_diameter/diam_message.h

@@ -26,8 +26,8 @@
  * - Module: \ref acc
  */
 
-#ifndef _AAA_DIAMETER_MSG_H
-#define _AAA_DIAMETER_MSG_H
+#ifndef _ACC_DIAM_MESSAGE_H_
+#define _ACC_DIAM_MESSAGE_H_
 
 #include "../../core/str.h"
 #include "../../core/mem/mem.h"