net: caif: added cfserl_release function

stable inclusion
from stable-v4.19.194
commit ef1461e1198e7ede8cea9b6cb437d5dbd17b5ac7
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I990B2
CVE: CVE-2021-47121

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ef1461e1198e7ede8cea9b6cb437d5dbd17b5ac7



---------------------------

commit bce130e7 upstream.

Added cfserl_release() function.

Cc: stable@vger.kernel.org
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Liu Jian <liujian56@huawei.com>