changed xmlErrValidWarning to use ctxt->warning instead of ctxt->error for

* valid.c: changed xmlErrValidWarning to use ctxt->warning
  instead of ctxt->error for its reports (bug #160662)
diff --git a/valid.c b/valid.c
index 28111a5..60ac127 100644
--- a/valid.c
+++ b/valid.c
@@ -220,7 +220,7 @@
     void *data = NULL;
 
     if (ctxt != NULL) {
-        channel = ctxt->error;
+        channel = ctxt->warning;
         data = ctxt->userData;
 	/* Use the special values to detect if it is part of a parsing
 	   context */