PDF export of PDF images: avoid invalid offset for not used jpeg bitmaps

I missed the JPEG case in commit
30102ded (vcl PDF export, norefxobj:
avoid replacement bitmap, 2017-03-29).

Change-Id: If1f74c7873d05d5d7da5eb881626d4e5e535a0a1
Reviewed-on: https://gerrit.libreoffice.org/36272Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>

vcl/source/gdi/pdfwriter_impl.cxx

@@ -11696,7 +11696,8 @@ void PDFWriterImpl::drawJPGBitmap( SvStream& rDCTData, bool bIsTrueColor, const
     {
         m_aJPGs.emplace( m_aJPGs.begin() );
         JPGEmit& rEmit = m_aJPGs.front();
-        rEmit.m_nObject     = createObject();
+        if (!hasPdfData(rGraphic, m_aContext.UseReferenceXObject) || m_aContext.UseReferenceXObject)
+            rEmit.m_nObject = createObject();
         rEmit.m_aID         = aID;
         rEmit.m_pStream.reset( pStream );
         rEmit.m_bTrueColor  = bIsTrueColor;