Fix all header defines

src/qt/guiutil.h

@@ -2,8 +2,8 @@
 // Distributed under the MIT/X11 software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#ifndef GUIUTIL_H
-#define GUIUTIL_H
+#ifndef BITCOIN_QT_GUIUTIL_H
+#define BITCOIN_QT_GUIUTIL_H
 
 #include "amount.h"
 
@@ -188,4 +188,4 @@ namespace GUIUtil
     QString formatPingTime(double dPingTime);
 } // namespace GUIUtil
 
-#endif // GUIUTIL_H
+#endif // BITCOIN_QT_GUIUTIL_H