crypto: cryptd - Assign statesize properly

cryptd_create_hash() fails by returning -EINVAL.  It is because after
8996eafd

 ("crypto: ahash - ensure statesize is non-zero") all ahash
drivers must have a non-zero statesize.

This patch fixes the problem by properly assigning the statesize.

Signed-off-by: Rui Wang <rui.y.wang@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>