[gnome-software] fwupd: Fix warning printing null value

[Richard Hughes <rhughes src gnome org>]

commit e668f6be33b23dfe311a23a93bbaebcfadfb8310
Author: Robert Ancell <robert ancell canonical com>
Date:   Thu Jan 23 13:07:16 2020 +1300

    fwupd: Fix warning printing null value

 plugins/fwupd/gs-plugin-fwupd.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/plugins/fwupd/gs-plugin-fwupd.c b/plugins/fwupd/gs-plugin-fwupd.c
index 1502e718..791be8f8 100644
--- a/plugins/fwupd/gs-plugin-fwupd.c
+++ b/plugins/fwupd/gs-plugin-fwupd.c
@@ -649,8 +649,8 @@ gs_plugin_fwupd_refresh_remote (GsPlugin *plugin,
                guint64 age = fwupd_remote_get_age (remote);
                guint tmp = age < G_MAXUINT ? (guint) age : G_MAXUINT;
                if (tmp < cache_age) {
-                       g_debug ("%s is only %u seconds old, so ignoring refresh",
-                                filename_sig, tmp);
+                       g_debug ("fwupd remote is only %u seconds old, so ignoring refresh",
+                                tmp);
                        return TRUE;
                }
        }