[libxml2] Fix previous change to node sort order

[Nick Wellnhofer <nwellnhof src gnome org>]

commit 3eaedba1b64180668fdab7ad2eba549586017bf3
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Sat Jul 11 14:27:34 2015 +0200

    Fix previous change to node sort order
    
    Commit ba58f23 broke comparison of nodes from different documents.
    Thanks to Olli Pottonen for the report.

 xpath.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/xpath.c b/xpath.c
index e9f5bf9..935fcff 100644
--- a/xpath.c
+++ b/xpath.c
@@ -361,14 +361,14 @@ turtle_comparison:
     /*
      * compute depth to root
      */
-    for (depth2 = 0, cur = node2; cur != NULL; cur = cur->parent) {
-       if (cur == node1)
+    for (depth2 = 0, cur = node2; cur->parent != NULL; cur = cur->parent) {
+       if (cur->parent == node1)
            return(1);
        depth2++;
     }
     root = cur;
-    for (depth1 = 0, cur = node1; cur != NULL; cur = cur->parent) {
-       if (cur == node2)
+    for (depth1 = 0, cur = node1; cur->parent != NULL; cur = cur->parent) {
+       if (cur->parent == node2)
            return(-1);
        depth1++;
     }