block: Ues bi_pool for bio_integrity_alloc()

block: Ues bi_pool for bio_integrity_alloc()

Now that bios keep track of where they were allocated from,
bio_integrity_alloc_bioset() becomes redundant.

Remove bio_integrity_alloc_bioset() and drop bio_set argument from the
related functions and make them use bio->bi_pool.

Signed-off-by: Kent Overstreet <[email protected]>
CC: Jens Axboe <[email protected]>
CC: Martin K. Petersen <[email protected]>
Acked-by: Tejun Heo <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>