engines/e_devcrypto.c: fix cipher_ctrl function

This fixes commit c703a808

, which had a mistake in cipher_ctrl function.

Move the /dev/crypto session cleanup code to its own function.

Signed-off-by: Eneas U de Queiroz <cote2004-github@yahoo.com>

Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/8213)