Add a helper to stop open coding the container_of operations to get
from the clone bio to the tio structure.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-3-hch@lst.de


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