Replace deprecated QMutex(Recursive) with QRecursiveMutex

plugins/samplesource/testsource/testsourceworker.cpp

@@ -60,7 +60,6 @@ TestSourceWorker::TestSourceWorker(SampleSinkFifo* sampleFifo, QObject* parent)
 	m_fcPosShift(0),
     m_throttlems(TESTSOURCE_THROTTLE_MS),
     m_throttleToggle(false),
-    m_mutex(QMutex::Recursive),
     m_histoCounter(0)
 {
     connect(&m_inputMessageQueue, SIGNAL(messageEnqueued()), this, SLOT(handleInputMessages()), Qt::QueuedConnection);

plugins/samplesource/testsource/testsourceworker.h

@@ -105,7 +105,7 @@ private:
     QTimer m_timer;
     QElapsedTimer m_elapsedTimer;
     bool m_throttleToggle;
-    QMutex m_mutex;
+    QRecursiveMutex m_mutex;
 
     MessageQueue m_inputMessageQueue;