Fix hang at end of installation.

Task-number: QTIFW-416
Task-number: QTCREATORBUG-10974

Change-Id: Ib2759cda2e24915880e134a13af126572094bd66
Reviewed-by: Eike Ziller <eike.ziller@digia.com>

dist/installer/ifw/packages/org.qtproject.qtcreator.application/meta/installscript.qs

@@ -191,8 +191,9 @@ function isRoot()
 
 Component.prototype.installationFinishedPageIsShown = function()
 {
+    isroot = isRoot();
     try {
-        if (component.installed && installer.isInstaller() && installer.status == QInstaller.Success && !isRoot()) {
+        if (component.installed && installer.isInstaller() && installer.status == QInstaller.Success && !isroot) {
             installer.addWizardPageItem( component, "LaunchQtCreatorCheckBoxForm", QInstaller.InstallationFinished );
         }
     } catch(e) {
@@ -203,7 +204,7 @@ Component.prototype.installationFinishedPageIsShown = function()
 Component.prototype.installationFinished = function()
 {
     try {
-        if (component.installed && installer.isInstaller() && installer.status == QInstaller.Success && !isRoot()) {
+        if (component.installed && installer.isInstaller() && installer.status == QInstaller.Success && !isroot) {
             var isLaunchQtCreatorCheckBoxChecked = component.userInterface("LaunchQtCreatorCheckBoxForm").launchQtCreatorCheckBox.checked;
             if (isLaunchQtCreatorCheckBoxChecked)
                 installer.executeDetached(component.qtCreatorBinaryPath, new Array(), "@homeDir@");