mm/hugetlb: use helper function range_in_vma() in page_table_shareable()

We could use helper function range_in_vma() to check whether the vma is in
the desired range to simplify the code.

Link: https://lkml.kernel.org/r/20210204112949.43051-1-linmiaohe@huawei.com


Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>