Use the proper helper to read the block device size.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NKees Cook <keescook@chromium.org>
Reviewed-by: NAnand Jain <anand.jain@oracle.com>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Acked-by: NDavid Sterba <dsterba@suse.com>
Link: https://lore.kernel.org/r/20211018101130.1838532-13-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>