This reverts commit 7cbcb219,
misapplied upstream commit 5837c80e.

The upstream commit was applied twice to stable-3.12, the second time
to bio_integrity_generate. Revert this second application.

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>