crypto: api - Remove completion function scaffolding

This patch removes the temporary scaffolding now that the comletion
function signature has been converted.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>