tty_audit: make data of tty_audit_log() const

'data' are only read (passed down to audit_log_n_hex()), so they can be
const -- the same what is expected in audit_log_n_hex(). Only a minor
cleanup to be consistent.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230621101611.10580-7-jirislaby@kernel.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>