Fix to return a negative error code -EINVAL instead of 0.

Fixes: 0cec19c7 ("crypto: qat - add support for compression for 4xxx")
Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Acked-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>