block: Call blkdev_dio_unaligned() from blkdev_direct_IO()

blkdev_dio_unaligned() is called from __blkdev_direct_IO(),
__blkdev_direct_IO_simple(), and __blkdev_direct_IO_async(), and all these
are only called from blkdev_direct_IO().

Move the blkdev_dio_unaligned() call to the common callsite,
blkdev_direct_IO().

Pass those functions the bdev pointer from blkdev_direct_IO(), as it is
non-trivial to look up.

Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20240415122020.1541594-1-john.g.garry@oracle.com


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