selftests: ublk: add ublk auto integrity test

selftests: ublk: add ublk auto integrity test

The end-to-end integrity ublk selftest test_integrity_02 requires a
relatively recent fio version to support I/O with integrity buffers. Add
a version test_integrity_03 that uses the block layer's auto integrity
path instead. The auto integrity code doesn't check the application tag,
and doesn't indicate the bad guard/ref tag (just returns EILSEQ). But
it's a good smoke-test of the ublk integrity code and provides coverage
of the auto integrity path as well.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Link: https://patch.msgid.link/20260421200901.1528842-4-csander@purestorage.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>