fix a problem in externalSubsetSplit with a patch from Ashwin Daniel

* xmlschemas.c: fix a problem in externalSubsetSplit with a patch
  from Ashwin
Daniel

svn path=/trunk/; revision=3716
diff --git a/xmlschemas.c b/xmlschemas.c
index 01a9c3c..d57ba9f 100644
--- a/xmlschemas.c
+++ b/xmlschemas.c
@@ -28108,8 +28108,8 @@
 {
     xmlSchemaSAXPlugPtr ctxt = (xmlSchemaSAXPlugPtr) ctx;
     if ((ctxt != NULL) && (ctxt->user_sax != NULL) &&
-        (ctxt->user_sax->internalSubset != NULL))
-	ctxt->user_sax->internalSubset(ctxt->user_data, name, ExternalID,
+        (ctxt->user_sax->externalSubset != NULL))
+	ctxt->user_sax->externalSubset(ctxt->user_data, name, ExternalID,
 	                               SystemID);
 }