tdf#89329: use unique_ptr for pImpl in fileview

Change-Id: Ief2fd163cc024b4a654a32c24cef832c68ad5e96
Reviewed-on: https://gerrit.libreoffice.org/25482Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noelgrandin@gmail.com>

include/svtools/fileview.hxx

@@ -70,7 +70,7 @@ struct FileViewAsyncAction
 class SVT_DLLPUBLIC SvtFileView : public Control
 {
 private:
-    SvtFileView_Impl*              mpImp;
+    std::unique_ptr<SvtFileView_Impl>              mpImpl;
     bool                           bSortColumn;
     css::uno::Sequence< OUString > mpBlackList;