pktcdvd: don't rely on bio_init() preserving bio->bi_io_vec

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 540bf36..ba2f550 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -1133,16 +1133,20 @@
 	 * Schedule reads for missing parts of the packet.
 	 */
 	for (f = 0; f < pkt->frames; f++) {
+		struct bio_vec *vec;
+
 		int p, offset;
 		if (written[f])
 			continue;
 		bio = pkt->r_bios[f];
+		vec = bio->bi_io_vec;
 		bio_init(bio);
 		bio->bi_max_vecs = 1;
 		bio->bi_sector = pkt->sector + f * (CD_FRAMESIZE >> 9);
 		bio->bi_bdev = pd->bdev;
 		bio->bi_end_io = pkt_end_io_read;
 		bio->bi_private = pkt;
+		bio->bi_io_vec = vec;
 
 		p = (f * CD_FRAMESIZE) / PAGE_SIZE;
 		offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
@@ -1439,6 +1443,7 @@
 	pkt->w_bio->bi_bdev = pd->bdev;
 	pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
 	pkt->w_bio->bi_private = pkt;
+	pkt->w_bio->bi_io_vec = bvec;
 	for (f = 0; f < pkt->frames; f++)
 		if (!bio_add_page(pkt->w_bio, bvec[f].bv_page, CD_FRAMESIZE, bvec[f].bv_offset))
 			BUG();