Missing dispose of dialog

...causing crash later at

> SfxItemPool::GetFrozenIdRanges() const
> SfxItemSet::~SfxItemSet()
> SfxTabDialog::dispose()
> ScRefHdlrImpl<ScValidationDlg, SfxTabDialog, false>::dispose()
> ScValidationDlg::dispose()
> OutputDevice::disposeOnce()
> VclPtr<vcl::Window>::disposeAndClear()
> vcl::LazyDeletor::~LazyDeletor()
> vcl::LazyDelete::flush()
> ImplYield(bool, bool, unsigned long)
> Application::Yield()

Change-Id: Ia4ae95cbbf4b5660ed08058b67ab674029c0b437

sc/source/ui/view/cellsh2.cxx

@@ -849,7 +849,7 @@ void ScCellShell::ExecuteDB( SfxRequest& rReq )
                     }
 
                     // cell range picker
-                    auto pDlg = VclPtr<ScValidationDlg>::Create(nullptr, &aArgSet, pTabViewShell);
+                    ScopedVclPtr<ScValidationDlg> pDlg(VclPtr<ScValidationDlg>::Create(nullptr, &aArgSet, pTabViewShell));
 
                     short nResult = pDlg->Execute();
                     if ( nResult == RET_OK )