Unit tests: Explicitly check for success from runner.

We will otherwise miss runner failures for any file that does not
contribute to the diagnostics count.
Note: The tool can also fail during the building stage, but in this case
we will get notified by the signal spy timing out.

Change-Id: Ia9aa797d658b1752e3da6e08a652ee55868955ba
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@theqtcompany.com>

plugins/clangstaticanalyzer/clangstaticanalyzerruncontrol.cpp

@@ -214,6 +214,7 @@ QList<ClangStaticAnalyzerRunControl::AnalyzeUnit> ClangStaticAnalyzerRunControl:
 
 bool ClangStaticAnalyzerRunControl::startEngine()
 {
+    m_success = false;
     emit starting(this);
 
     QTC_ASSERT(m_projectInfo.isValid(), emit finished(); return false);
@@ -277,6 +278,7 @@ bool ClangStaticAnalyzerRunControl::startEngine()
     m_runners.clear();
     const int parallelRuns = ClangStaticAnalyzerSettings::instance()->simultaneousProcesses();
     QTC_ASSERT(parallelRuns >= 1, emit finished(); return false);
+    m_success = true;
     while (m_runners.size() < parallelRuns && !m_unitsToProcess.isEmpty())
         analyzeNextFile();
     return true;
@@ -373,6 +375,7 @@ void ClangStaticAnalyzerRunControl::onRunnerFinishedWithFailure(const QString &e
     qCDebug(LOG) << "onRunnerFinishedWithFailure:" << errorMessage << errorDetails;
 
     ++m_filesNotAnalyzed;
+    m_success = false;
     const QString filePath = qobject_cast<ClangStaticAnalyzerRunner *>(sender())->filePath();
     appendMessage(tr("Failed to analyze \"%1\": %2").arg(filePath, errorMessage)
                   + QLatin1Char('\n')