crypto: Move cipher->driver init to qcrypto_*_cipher_ctx_new

The class vtable should be set by the class initializer.
This will also allow additional subclassing, reducing the
amount of indirection in the hierarchy.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
6 files changed