tdf#122127 Crash in FORM EDIT using drag drop to move control in dataform

regression from
    commit 2629aac31142449312f77c5843ea209cc810acb4
    Date:   Tue Oct 23 09:47:10 2018 +0200
    clang-tidy performance-unnecessary-copy-init in svx

Change-Id: I4210c328145d062d8b72f09dcff3280e11c6bc36
Reviewed-on: https://gerrit.libreoffice.org/65394
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
diff --git a/svx/source/form/navigatortree.cxx b/svx/source/form/navigatortree.cxx
index bdf2a97..ab967ce 100644
--- a/svx/source/form/navigatortree.cxx
+++ b/svx/source/form/navigatortree.cxx
@@ -1000,7 +1000,7 @@
        DBG_ASSERT( DND_ACTION_COPY != _nAction, "NavigatorTree::implExecuteDataTransfer: somebody changed the logics!" );

        // list of dragged entries
        const ListBoxEntrySet& aDropped = _rData.selected();
        const ListBoxEntrySet aDropped = _rData.selected();
        DBG_ASSERT(!aDropped.empty(), "NavigatorTree::implExecuteDataTransfer: no entries!");

        // shell and model