crypto: s5p-sss - Fix minor coding style violations

Improve a little bit code readability and use dev_info/err for printing
messages.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>