blk-integrity: remove seed for user mapped buffers

blk-integrity: remove seed for user mapped buffers

The seed is only used for kernel generation and verification. That
doesn't happen for user buffers, so passing the seed around doesn't
accomplish anything.

Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Link: https://lore.kernel.org/r/20241016201309.1090320-1-kbusch@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>