tdf#160564 Treat xlink:type for embedded chart

xlink:type is a valid attribute for chart:chart according to ODF [1]
As this attribute is not yet used, this change just avoids the warning message

[1] https://docs.oasis-open.org/office/OpenDocument/v1.3/os/part3-schema/OpenDocument-v1.3-os-part3-schema.html#__RefHeading__1419428_253892949

Change-Id: I836c8ff4a284bafa8e0c8049ae6ae60c9fbe7a4c
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/165853
Reviewed-by: Laurent Balland <laurent.balland@mailo.fr>
Tested-by: Jenkins
diff --git a/xmloff/source/chart/SchXMLChartContext.cxx b/xmloff/source/chart/SchXMLChartContext.cxx
index 540f39c..418bea8 100644
--- a/xmloff/source/chart/SchXMLChartContext.cxx
+++ b/xmloff/source/chart/SchXMLChartContext.cxx
@@ -327,6 +327,9 @@ void SchXMLChartContext::startFastElement( sal_Int32 /*nElement*/,
            case XML_ELEMENT(LO_EXT, XML_DATA_PILOT_SOURCE):
                msDataPilotSource = aIter.toString();
                break;
            case XML_ELEMENT( XLINK, XML_TYPE ):
                // Ignored for now.
            break;
            case XML_ELEMENT(XLINK, XML_HREF):
                m_aXLinkHRefAttributeToIndicateDataProvider = aIter.toString();
                break;