hugetlbfs: replace hugetlb_vma_lock with invalidate_lock

Replace the custom hugetlbfs VMA locking code with the recently introduced
invalidate_lock.  This greatly simplifies things.

However, this is a large enough change that it should probably go in
separately from the other changes.

Another question is whether this simplification hurts scalability for
certain workloads.

Link: https://lkml.kernel.org/r/20231006040020.3677377-5-riel@surriel.com


Signed-off-by: Rik van Riel <riel@surriel.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>