crypto: cbc - Ensure statesize is zero

The cbc template should not be applied on stream ciphers, especially
ones that have internal state.  Enforce this by checking the state
size when the instance is created.

Reported-by:  <syzbot+050eeedd6c285d8c42f2@syzkaller.appspotmail.com>
Fixes: 47309ea1

 ("crypto: arc4 - Add internal state")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>