[gnome-software] trivial: Fix up a potential NULL dereference

[Richard Hughes <rhughes src gnome org>]

commit 949bac6e8dd27a07e0b4d44199b741ff8bf50b6b
Author: Richard Hughes <richard hughsie com>
Date:   Tue Sep 10 10:27:28 2013 +0100

    trivial: Fix up a potential NULL dereference
    
    Spotted by clang...

 src/plugins/appstream-cache.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/plugins/appstream-cache.c b/src/plugins/appstream-cache.c
index baa6f5a..5c9fe40 100644
--- a/src/plugins/appstream-cache.c
+++ b/src/plugins/appstream-cache.c
@@ -552,7 +552,7 @@ appstream_cache_parse_file (AppstreamCache *cache,
        if (len < 0)
                ret = FALSE;
 out:
-       if (helper->item_temp)
+       if (helper != NULL && helper->item_temp != NULL)
                appstream_app_free (helper->item_temp);
        if (info != NULL)
                g_object_unref (info);