try and silence coverity#1371452 Wrapper object use after free

Change-Id: I52ac98481a1a98c40ad8d6a31d8868b233337ec9
diff --git a/filter/source/xsltfilter/LibXSLTTransformer.cxx b/filter/source/xsltfilter/LibXSLTTransformer.cxx
index 4f9230b..743a841 100644
--- a/filter/source/xsltfilter/LibXSLTTransformer.cxx
+++ b/filter/source/xsltfilter/LibXSLTTransformer.cxx
@@ -327,6 +327,7 @@ namespace XSLT
            m_transformer->error(msg);
        }
        closeOutput();
        m_tcontext->_private = nullptr;
        oh.reset();
        xsltFreeStylesheet(styleSheet);
        xsltFreeTransformContext(m_tcontext);