crypto: tegra - remove redundant error check on ret

Currently there is an unnecessary error check on ret without a proceeding
assignment to ret that needs checking. The check is redundant and can be
removed.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Acked-by: Akhil R <akhilrajeev@nvidia.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>