block: Initialize local_err in bdrv_append_temp_snapshot Cc: qemu-stable@nongnu.org Signed-off-by: Fam Zheng <famz@redhat.com> Message-id: 1436156684-16526-1-git-send-email-famz@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>