Replace include guards with #pragma once

Change-Id: I16adc78d397e3239440206e8e70ebbd5e0963adb
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/directory.hpp b/directory.hpp
index 9a12a3c..0a9d580 100644
--- a/directory.hpp
+++ b/directory.hpp
@@ -1,5 +1,4 @@
-#ifndef __DIRECTORY_H
-#define __DIRECTORY_H
+#pragma once
 
 #include <string>
 #include <dirent.h>
@@ -17,6 +16,4 @@
         DIR* dirp;
 };
 
-#endif
-
 // vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4