Revert "block: Fix UAF in bd_link_disk_holder()"

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I60Q98


CVE: NA

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Official solution will be applied to mainline, and this solution can't
fix uaf for 'bd_holder_dir' thoroughly. hence revert this temporary
solution. Officail solution will be backported in the next patch.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>