tdf#147668: Destroy still needs to do its work when called from disposing

Regression introduced with d4257daba1155ebccbfebea99bad0e4152ca9b08 "use
comphelper::WeakComponentImplHelper in MenuBarManager" changing

-    if ( rBHelper.bDisposed )
+    if ( m_bDisposed )

in MenuBarManager::Destroy, but where comphelper::WeakComponentImplHelper sets
m_bDisposed to true before calling disposing.

And Destroy is only called from disposing, so the check can just be removed.

Change-Id: I2625dff9fbb333435a0d1478b0f285c21cd3ee15
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/132075
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>
Tested-by: Jenkins
diff --git a/framework/source/uielement/menubarmanager.cxx b/framework/source/uielement/menubarmanager.cxx
index 7b856a0..49b4092f 100644
--- a/framework/source/uielement/menubarmanager.cxx
+++ b/framework/source/uielement/menubarmanager.cxx
@@ -140,9 +140,6 @@ void MenuBarManager::Destroy()
{
    SolarMutexGuard aGuard;

    if ( m_bDisposed )
        return;

    // stop asynchronous settings timer and
    // release deferred item container reference
    m_aAsyncSettingsTimer.Stop();