block: fix kabi broken in struct hd_part

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8HQ3W



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A new field is added in struct hd_part, fix kabi broken by using
KABI_FILL_HOLE.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>