[ostree] libostree: Adjust `cleanup_ref_prefix` to use ostree_repo_list_refs_ext

[Colin Walters <walters src gnome org>]

commit 3e3621b7b679a0975a84af168b1239324e43e324
Author: Giuseppe Scrivano <gscrivan redhat com>
Date:   Wed Mar 2 10:14:23 2016 +0100

    libostree: Adjust `cleanup_ref_prefix` to use ostree_repo_list_refs_ext
    
    Signed-off-by: Giuseppe Scrivano <gscrivan redhat com>

 src/libostree/ostree-sysroot-cleanup.c |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)
---
diff --git a/src/libostree/ostree-sysroot-cleanup.c b/src/libostree/ostree-sysroot-cleanup.c
index 718c16e..f053ac0 100644
--- a/src/libostree/ostree-sysroot-cleanup.c
+++ b/src/libostree/ostree-sysroot-cleanup.c
@@ -401,7 +401,7 @@ cleanup_ref_prefix (OstreeRepo         *repo,
 
   prefix = g_strdup_printf ("ostree/%d/%d", bootversion, subbootversion);
 
-  if (!ostree_repo_list_refs (repo, prefix, &refs, cancellable, error))
+  if (!ostree_repo_list_refs_ext (repo, prefix, &refs, OSTREE_REPO_LIST_REFS_EXT_NONE, cancellable, error))
     goto out;
 
   if (!ostree_repo_prepare_transaction (repo, NULL, cancellable, error))
@@ -410,8 +410,7 @@ cleanup_ref_prefix (OstreeRepo         *repo,
   g_hash_table_iter_init (&hashiter, refs);
   while (g_hash_table_iter_next (&hashiter, &hashkey, &hashvalue))
     {
-      const char *suffix = hashkey;
-      g_autofree char *ref = g_strconcat (prefix, "/", suffix, NULL);
+      const char *ref = hashkey;
       ostree_repo_transaction_set_refspec (repo, ref, NULL);
     }