fix a possible double reference on 'ticket'
when peer_cert/peer_cert_digest calloc failed.
Cherry-pick from https://github.com/Mbed-TLS/mbedtls/commit/eb490aabf6a9f47c074ec476d0d4997c2362cdbcSigned-off-by: Nmaoyufeng <maoyufeng3@huawei.com>