/dev/crypto engine: give CIOCFSESSION the actual sess-id

We passed that ioctl a pointer to the whole session_op structure,
which wasn't quite right.

Notified by David Legault.

Fixes #7302

Reviewed-by: Kurt Roeckx <kurt@roeckx.be>
(Merged from https://github.com/openssl/openssl/pull/7304)