disable stealing by default

hulk inclusion
category: feature
bugzilla: 38261, https://bugzilla.openeuler.org/show_bug.cgi?id=23


CVE: NA

---------------------------

Steal tasks to improve CPU utilization can solve some performance
problems such as mysql, but not all scenarios are optimized, such as
hackbench.

So turn off by default.

Signed-off-by: Cheng Jian <cj.chengjian@huawei.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>