Emit parsing finished at the very end of the background thread

Otherwise, we might get unlucky and crash when our tests await this
signal and then destroy the parser object as a result, leading to
crashes.

Author: milianw

src/parsers/perf/perfparser.cpp

@@ -1563,14 +1563,14 @@ void PerfParser::startParseFile(const QString& path)
             emit tracepointDataAvailable(d.tracepointResult);
             emit eventsAvailable(d.eventResult);
             emit frequencyDataAvailable(d.frequencyResult);
-            emit parsingFinished();
-
             emit threadNamesAvailable(d.commands);
 
             if (d.m_numSamplesWithMoreThanOneFrame == 0) {
                 emit parserWarning(tr("Samples contained no call stack frames. Consider passing <code>--call-graph "
                                       "dwarf</code> to <code>perf record</code>."));
             }
+
+            emit parsingFinished();
         };
 
         if (path.endsWith(QLatin1String(".perfparser"))) {