[ostree] main: Print "error: " prefix on errors

[Colin Walters <walters src gnome org>]

commit 8cb348315eff81456b1e0b70c554558b4128df06
Author: Colin Walters <walters verbum org>
Date:   Wed Jul 10 13:25:15 2013 -0400

    main: Print "error: " prefix on errors
    
    It's just clearer that something went wrong.

 src/ostree/main.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/ostree/main.c b/src/ostree/main.c
index 3863a14..b20cdbb 100644
--- a/src/ostree/main.c
+++ b/src/ostree/main.c
@@ -71,7 +71,7 @@ main (int    argc,
 
   if (error != NULL)
     {
-      g_printerr ("%s\n", error->message);
+      g_printerr ("error: %s\n", error->message);
       g_error_free (error);
     }