crypto: hisilicon/qm - add concurrency protection for variable err_threshold

crypto: hisilicon/qm - add concurrency protection for variable err_threshold

The isolate_strategy_store function is not protected
by a lock. If sysfs operations and functions that depend
on the err_threshold variable,such as qm_hw_err_isolate(),
execute concurrently, the outcome will be unpredictable.
Therefore, concurrency protection should be added for
the err_threshold variable.

Signed-off-by: nieweiqiang <nieweiqiang@huawei.com>
Signed-off-by: Chenghai Huang <huangchenghai2@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>