mm: hugetlb_vmemmap: cleanup hugetlb_free_vmemmap_enabled*

mainline inclusion
from mainline-v5.19-rc1
commit f10f1442
category: feature
bugzilla: 187198, https://gitee.com/openeuler/kernel/issues/I5GVFO
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f10f1442c309ccef7a80ba3dc4abde0978e86fb4

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

The word of "free" is not expressive enough to express the feature of
optimizing vmemmap pages associated with each HugeTLB, rename this keywork
to "optimize".  In this patch , cheanup the static key and
hugetlb_free_vmemmap_enabled() to make code more expressive.

Link: https://lkml.kernel.org/r/20220404074652.68024-3-songmuchun@bytedance.com


Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Conflicts:
	mm/memory_hotplug.c
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>