Remove unused static method

The only use of this method got removed already in commit bebae37376.

Change-Id: I9757cbe34710efd9a9d31c74f81e01da40453ff9
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>

src/corelib/io/qstandardpaths_win.cpp

@@ -86,15 +86,6 @@ static void appendOrganizationAndApp(QString &path) // Courtesy qstandardpaths_u
 #endif
 }
 
-static inline QString displayName(QStandardPaths::StandardLocation type)
-{
-#ifndef QT_BOOTSTRAPPED
-    return QStandardPaths::displayName(type);
-#else
-    return QString::number(type);
-#endif
-}
-
 static inline void appendTestMode(QString &path)
 {
     if (QStandardPaths::isTestModeEnabled())