Use the right array index to reference the last
element of rq->biotail->bi_io_vec[]
Signed-off-by: NWenbo Wang <wenbo.wang@memblaze.com>
Reviewed-by: NChong Yuan <chong.yuan@memblaze.com>
Fixes: 66cb45aa ("block: add support for limiting gaps in SG lists")
Cc: stable@kernel.org
Signed-off-by: NJens Axboe <axboe@fb.com>