[gnome-software/gnome-3-22] Add a missing error check to fix a common crash on LiveDVD media

[Kalev Lember <klember src gnome org>]

commit 3b0237f052b8b8671fd76457b11d26f334bbe3d3
Author: Richard Hughes <richard hughsie com>
Date:   Thu Dec 1 20:15:48 2016 +0000

    Add a missing error check to fix a common crash on LiveDVD media
    
    Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1393344

 src/plugins/gs-plugin-odrs.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/src/plugins/gs-plugin-odrs.c b/src/plugins/gs-plugin-odrs.c
index 098a3de..5507655 100644
--- a/src/plugins/gs-plugin-odrs.c
+++ b/src/plugins/gs-plugin-odrs.c
@@ -167,6 +167,8 @@ gs_plugin_odrs_refresh_ratings (GsPlugin *plugin,
                                          "odrs.json",
                                          GS_UTILS_CACHE_FLAG_WRITEABLE,
                                          error);
+       if (fn == NULL)
+               return FALSE;
        if (cache_age > 0) {
                guint tmp;
                g_autoptr(GFile) file = NULL;