crypto: ux500 - Adjust two condition checks in ux500_cryp_probe()

The local variable "cryp_error" was used only for two condition checks.

* Check the return values from these function calls directly instead.

* Delete this variable which became unnecessary with this refactoring.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>