LogCompressor: Add missing const in member functions

Signed-off-by: Patrick José Pereira <patrickelectric@gmail.com>

src/LogCompressor.cc

@@ -201,12 +201,12 @@ void LogCompressor::startCompression(bool holeFilling)
 	start();
 }
 
-bool LogCompressor::isFinished()
+bool LogCompressor::isFinished() const
 {
 	return !running;
 }
 
-int LogCompressor::getCurrentLine()
+int LogCompressor::getCurrentLine() const
 {
 	return currentDataLine;
 }

src/LogCompressor.h

@@ -26,8 +26,8 @@ public:
     LogCompressor(QString logFileName, QString outFileName="", QString delimiter="\t");
     /** @brief Start the compression of a raw, line-based logfile into a CSV file */
     void startCompression(bool holeFilling=false);
-    bool isFinished();
+    bool isFinished() const;
-    int getCurrentLine();
+    int getCurrentLine() const;
 
 protected:
     void run();                     ///< This function actually performs the compression. It's an overloaded function from QThread