applied a change suggested by Sean Griffin in bug #118494 about a memory

* xpath.c: applied a change suggested by Sean Griffin in bug
  #118494 about a memory leak in EXSLT
Daniel
diff --git a/xpath.c b/xpath.c
index 50ad7ee..16681b2 100644
--- a/xpath.c
+++ b/xpath.c
@@ -1038,6 +1038,9 @@
     }
     obj = valuePop(ctxt);
     ret = obj->nodesetval;
+    /* to fix memory leak of not clearing obj->user */
+    if (obj->boolval && obj->user != NULL)
+        xmlFreeNodeList((xmlNodePtr) obj->user);
     xmlXPathFreeNodeSetList(obj);
     return(ret);
 }