[gnome-ostree] testbase: Use Format.vprintf, not String.format

[Colin Walters <walters src gnome org>]

commit 44c39d83fd76a9314c888656a2ba6ed5567ad2f1
Author: Colin Walters <walters verbum org>
Date:   Thu Sep 5 19:49:35 2013 -0400

    testbase: Use Format.vprintf, not String.format
    
    Since we don't monkey patch it in.

 src/js/tasks/testbase.js |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/js/tasks/testbase.js b/src/js/tasks/testbase.js
index b8b7499..b9c468e 100644
--- a/src/js/tasks/testbase.js
+++ b/src/js/tasks/testbase.js
@@ -406,7 +406,7 @@ const TestBase = new Lang.Class({
                 let lastSlash = targetName.lastIndexOf('/');
                 let testedRefName = snapshot['osname'] + '/' + this.CompletedTag + 
targetName.substr(lastSlash);
                 this.ostreeRepo.write_ref(null, testedRefName, targetRev);
-                print("Wrote ref: %s => %s".format(testedRefName, targetRev));
+                print(Format.vprintf("Wrote ref: %s => %s", [testedRefName, targetRev]));
             }
         } else {
             print("No build json found, not tagging");