net: caif: added cfserl_release function

commit bce130e7f392ddde8cfcb09927808ebd5f9c8669 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>