block: open accurate iostat account by default

hulk inclusion
category: bugfix
bugzilla: 187044, https://gitee.com/openeuler/kernel/issues/I5F2BY


CVE: NA

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Open accurate iostat account by default with setting the
"precise_iostat = 1" when initializing.

Signed-off-by: Zhang Wensheng <zhangwensheng5@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>