dhugetlb: use enable_dhugetlb to disable huge_memory

hulk inclusion
category: feature
bugzilla: 46904, https://gitee.com/openeuler/kernel/issues/I6BDME


CVE: NA

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If hugepage_init() is called before hugetlb_init(), dhugetlb_enabled
has not been initialized, we should use enable_dhugetlb instead.

Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>