fixed to not send NULL to %s printing cleaning up some of the regression

* HTMLparser.c: fixed to not send NULL to %s printing
* python/tests/error.py result/HTML/doc3.htm.err
  result/HTML/test3.html.err result/HTML/wired.html.err
  result/valid/t8.xml.err result/valid/t8a.xml.err: cleaning
  up some of the regression tests error
Daniel
diff --git a/HTMLparser.c b/HTMLparser.c
index 881821a..ba12ecc 100644
--- a/HTMLparser.c
+++ b/HTMLparser.c
@@ -1132,7 +1132,7 @@
         if ((info != NULL) && (info->endTag == 3)) {
             htmlParseErr(ctxt, XML_ERR_TAG_NAME_MISMATCH,
 	                 "Opening and ending tag mismatch: %s and %s\n",
-			 NULL, NULL);
+			 newtag, ctxt->name);
         }
         if ((ctxt->sax != NULL) && (ctxt->sax->endElement != NULL))
             ctxt->sax->endElement(ctxt->userData, ctxt->name);