Use newly added mm function unpin_user_folio() to put refs by npages
count.

Signed-off-by: Kundan Kumar <kundan.kumar@samsung.com>
Tested-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20240911064935.5630-5-kundan.kumar@samsung.com


Signed-off-by: Jens Axboe <axboe@kernel.dk>