Wholesale conversion to #pragma once

Kudos to cgmb and https://github.com/cgmb/guardonce

Change-Id: Ifa8970734b8d43fd08c9260c645bdb0228633791
Reviewed-by: Tobias Hunger <tobias.hunger@theqtcompany.com>

src/libs/utils/fileutils.h

@@ -23,8 +23,7 @@
 **
 ****************************************************************************/
 
-#ifndef FILEUTILS_H
-#define FILEUTILS_H
+#pragma once
 
 #include "utils_global.h"
 
@@ -207,5 +206,3 @@ QTCREATOR_UTILS_EXPORT uint qHash(const Utils::FileName &a);
 QT_END_NAMESPACE
 
 Q_DECLARE_METATYPE(Utils::FileName)
-
-#endif // FILEUTILS_H