Mac: Fix running Qt applications

The executable was not resolved to the app bundle, broke with
95169eb8e3

Task-number: QTCREATORBUG-8271
Change-Id: I374cb6f3935878db4d30c944ce56ad424e4e250b
Reviewed-by: Daniel Teske <daniel.teske@digia.com>

src/plugins/qt4projectmanager/qt4nodes.cpp

@@ -2177,9 +2177,10 @@ TargetInformation Qt4ProFileNode::targetInformation(QtSupport::ProFileReader *re
 
     if (Utils::HostOsInfo::isMacHost()
             && reader->values(QLatin1String("CONFIG")).contains(QLatin1String("app_bundle"))) {
-        result.workingDir += QLatin1Char('/')
-                           + result.target
+        const QString infix = QLatin1Char('/') + result.target
                 + QLatin1String(".app/Contents/MacOS");
+        result.workingDir += infix;
+        destDir += infix;
     }
 
     result.workingDir = QDir::cleanPath(result.workingDir);