[gnome-software] flatpak: Fix an uninitialized variable

[Kalev Lember <klember src gnome org>]

commit 9c39e984f7a7fb078f86af172a674f2132e05590
Author: Kalev Lember <klember redhat com>
Date:   Thu Feb 28 16:33:40 2019 +0100

    flatpak: Fix an uninitialized variable

 plugins/flatpak/gs-plugin-flatpak.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/plugins/flatpak/gs-plugin-flatpak.c b/plugins/flatpak/gs-plugin-flatpak.c
index bf303732..3844ca97 100644
--- a/plugins/flatpak/gs-plugin-flatpak.c
+++ b/plugins/flatpak/gs-plugin-flatpak.c
@@ -665,7 +665,7 @@ gs_plugin_update (GsPlugin *plugin,
                   GCancellable *cancellable,
                   GError **error)
 {
-       GsFlatpak *flatpak;
+       GsFlatpak *flatpak = NULL;
        g_autoptr(FlatpakTransaction) transaction = NULL;
        g_autoptr(GsAppList) list_tmp = gs_app_list_new ();