QmlProfiler: managing failed starts gracefully

Change-Id: Ice0debcb6b83977b8f50dd154687e7c5c6abac7b
Reviewed-on: http://codereview.qt.nokia.com/2113
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Kai Koehne <kai.koehne@nokia.com>

src/plugins/valgrind/valgrindengine.cpp

@@ -77,7 +77,7 @@ ValgrindEngine::~ValgrindEngine()
     delete m_progress;
 }
 
-void ValgrindEngine::start()
+bool ValgrindEngine::start()
 {
     emit starting(this);
 
@@ -115,6 +115,8 @@ void ValgrindEngine::start()
         runner()->startRemotely(sp.connParams);
     else
         runner()->start();
+
+    return true;
 }
 
 void ValgrindEngine::stop()