[libcalamares] Remove internal functions from the logging API

src/libcalamares/utils/Logger.cpp

@@ -86,7 +86,7 @@ log( const char* msg, unsigned int debugLevel, bool toDisk = true )
 }
 
 
-void
+static void
 CalamaresLogHandler( QtMsgType type, const QMessageLogContext& context, const QString& msg )
 {
     static QMutex s_mutex;
@@ -116,7 +116,7 @@ CalamaresLogHandler( QtMsgType type, const QMessageLogContext& context, const QS
 }
 
 
-QString
+static QString
 logFile()
 {
     return CalamaresUtils::appLogDir().filePath( "session.log" );

src/libcalamares/utils/Logger.h

@@ -58,9 +58,14 @@ namespace Logger
         virtual ~CDebug();
     };
 
-    DLLEXPORT void CalamaresLogHandler( QtMsgType type, const QMessageLogContext& context, const QString& msg );
+    /**
+     * @brief Start logging to the log file.
+     *
+     * Call this (once) to start logging to the log file (usually
+     * ~/.cache/calamares/session.log ). An existing log file is
+     * rolled over if it is too large.
+     */
     DLLEXPORT void setupLogfile();
-    DLLEXPORT QString logFile();
 
     /**
      * @brief Set a log level for future logging.