the change made to xmlXPathFuncLookupFunc was incompatible roll it back

* xpath.c include/libxml/xpathInternals.h: the change made to
  xmlXPathFuncLookupFunc was incompatible roll it back
Daniel
diff --git a/xpath.c b/xpath.c
index 9b07ce6..f712064 100644
--- a/xpath.c
+++ b/xpath.c
@@ -2291,9 +2291,9 @@
 
     if (ctxt->funcLookupFunc != NULL) {
 	xmlXPathFunction ret;
-	xmlXPathFuncLookupFunc *f;
+	xmlXPathFuncLookupFunc f;
 
-	f = (xmlXPathFuncLookupFunc *) ctxt->funcLookupFunc;
+	f = (xmlXPathFuncLookupFunc) ctxt->funcLookupFunc;
 	ret = f(ctxt->funcLookupData, name, NULL);
 	if (ret != NULL)
 	    return(ret);
@@ -2322,9 +2322,9 @@
 
     if (ctxt->funcLookupFunc != NULL) {
 	xmlXPathFunction ret;
-	xmlXPathFuncLookupFunc *f;
+	xmlXPathFuncLookupFunc f;
 
-	f = (xmlXPathFuncLookupFunc *) ctxt->funcLookupFunc;
+	f = (xmlXPathFuncLookupFunc) ctxt->funcLookupFunc;
 	ret = f(ctxt->funcLookupData, name, ns_uri);
 	if (ret != NULL)
 	    return(ret);