create-usb: Don't leave a GError set
create-usb: Don't leave a GError set

This commit avoids passing the error pointer to
flatpak_dir_get_deploy_data() in add_related() because we're not
treating the error as fatal. Otherwise the already-set error pointer can
get passed to flatpak_dir_update_summary() causing libostree to hit an
assertion failure when it checks (error == NULL || *error == NULL) in
_ostree_repo_lock_push().

Closes: #2110
Approved by: alexlarsson

matthiasclasen/flatpak,matthiasclasen/flatpak,flatpak/flatpak,flatpak/flatpak,matthiasclasen/flatpak,matthiasclasen/flatpak,flatpak/flatpak,matthiasclasen/flatpak,flatpak/flatpak,flatpak/flatpak