[glib] gio: Fix build with -Werror=format-security

[Rico Tzschichholz <ricotz src gnome org>]

commit d04faab3274ae06a318a87b08c499df7a797d39d
Author: Rico Tzschichholz <ricotz t-online de>
Date:   Tue Dec 18 21:32:01 2012 +0100

    gio: Fix build with -Werror=format-security

 gio/gunixvolume.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gio/gunixvolume.c b/gio/gunixvolume.c
index 5d8c7e9..24f14d5 100644
--- a/gio/gunixvolume.c
+++ b/gio/gunixvolume.c
@@ -310,7 +310,7 @@ eject_mount_cb (GPid     pid,
       g_task_return_new_error (task,
                                G_IO_ERROR, 
                                G_IO_ERROR_FAILED,
-                               data->error_string->str);
+                               "%s", data->error_string->str);
     }
   else
     g_task_return_boolean (task, TRUE);