crypto: bcm - Remove the unnecessary cast for PTR_ERR().

It's not necessary to specify 'int' casting for PTR_ERR().

Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>