remove unneeded specificity in unit test

The unit test should only be ensuring that the footnote is actually
written in the footnote section. The fix had nothing to do with the
style of the footnote.

Change-Id: I209f1f0a8cf896916eaf7e8002c92085926b508b
Reviewed-on: https://gerrit.libreoffice.org/37907Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Justin Luth <justin_luth@sil.org>

sw/qa/extras/ooxmlexport/ooxmlexport3.cxx

@@ -816,7 +816,7 @@ DECLARE_OOXMLEXPORT_TEST(testFootnoteParagraphTag, "testFootnote.docx")
     if (!pXmlFootnotes)
         return;
     assertXPath(pXmlFootnotes, "/w:footnotes/w:footnote[3]","id","2");
-    assertXPath(pXmlFootnotes, "/w:footnotes/w:footnote[3]/w:p/w:r/w:rPr/w:rStyle","val","Footnotereference");
+    assertXPath(pXmlFootnotes, "/w:footnotes/w:footnote[3]/w:p/w:r/w:footnoteRef", 1);
 }
 
 DECLARE_OOXMLEXPORT_TEST(testSpacingLineRule,"table_lineRule.docx")