Fix clearing signals already send after first part of audio data

Previous place for clearing received signal could errounsely
clear already sent signal which causes next signalState
comparison to fail on some platform.

Change-Id: Iaffdbbcab1ec9afa0be6f1f7b7aee62b981ee319
Reviewed-by: Yoann Lopes <yoann.lopes@theqtcompany.com>

tests/auto/integration/qaudiooutput/tst_qaudiooutput.cpp

@@ -702,11 +702,11 @@ void tst_QAudioOutput::push()
                 QVERIFY2((audioOutput.state() == QAudio::ActiveState), "didn't transition to ActiveState after receiving data");
                 QVERIFY2((audioOutput.error() == QAudio::NoError), "error state is not equal to QAudio::NoError after receiving data");
                 firstBuffer = false;
+                stateSignal.clear();
             }
         } else
             QTest::qWait(20);
     }
-    stateSignal.clear();
 
     // Wait until playback finishes
     QTest::qWait(3000); // 3 seconds should be plenty