crypto: pcrypt - Handle crypto_get_attr_type errors

I was concerned about the error handling for crypto_get_attr_type() in
pcrypt_alloc_aead().  Steffen Klassert pointed out that we could simply
avoid calling crypto_get_attr_type() if we passed the type and mask as a
parameters.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>