crypto: s5p-sss - remove unneeded local variable initialization

The initialization of 'err' local variable is not needed as it is
shortly after overwritten.

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