crypto: s5p-sss - consistently use local 'dev' variable in probe()

For code readability, the probe() function uses 'dev' variable instead
of '&pdev->dev', so update remaining places.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>