khugepaged: use helper function range_in_vma() in collapse_pte_mapped_thp()

Patch series "Cleanup for khugepaged".

This series contains cleanups to remove unnecessary out label and
meaningless !pte_present() check.  Also use helper function to simplify
the code.  More details can be found in the respective changelogs.

This patch (of 3):

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

Link: https://lkml.kernel.org/r/20210325135647.64106-1-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20210325135647.64106-2-linmiaohe@huawei.com


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