crypto: talitos - prune unneeded descriptor allocation param

talitos_edesc_alloc does not need hash_result param.
Checking whether dst scatterlist is NULL or not is all that is required.

Signed-off-by: Horia Geanta <horia.geanta@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>