Fixed compilation error (bug 340765) reported by dmacks with patch

* relaxng.c: Fixed compilation error (bug 340765) reported by
  dmacks with patch supplied by Graham Bennett.

ChangeLog

+Sat May  6 11:05:24 HKT 2006 William M. Brack <wbrack@mmm.com.hk>
+
+	* relaxng.c: Fixed compilation error (bug 340765) reported by
+	  dmacks with patch supplied by Graham Bennett.
+
 Thu May  4 19:14:03 CEST 2006 Kasimier Buchcik <libxml2-cvs@cazic.net>
 
 	* xmlschemas.c: We'll raise an internal error and stop

relaxng.c

@@ -7394,7 +7394,7 @@ xmlRelaxNGParse(xmlRelaxNGParserCtxtPtr ctxt)
     if (root == NULL) {
         xmlRngPErr(ctxt, (xmlNodePtr) doc,
 	           XML_RNGP_EMPTY, "xmlRelaxNGParse: %s is empty\n",
-                   (ctxt->URL ? ctxt->URL : "schemas"), NULL);
+                   (ctxt->URL ? ctxt->URL : BAD_CAST "schemas"), NULL);
 	
         xmlFreeDoc(ctxt->document);
         ctxt->document = NULL;