[ide] fix erroneous rq->buffer = NULL in ide-io.c:ide_dma_timeout_retry()

From: Prarit Bhargava <prarit@sgi.com>

Please see discussion related to this patch here,

http://marc.theaimsgroup.com/?l=linux-ide&m=110485007824374&w=2Acked-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

drivers/ide/ide-io.c

@@ -1212,7 +1212,7 @@ static ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int error)
 	rq->sector = rq->bio->bi_sector;
 	rq->current_nr_sectors = bio_iovec(rq->bio)->bv_len >> 9;
 	rq->hard_cur_sectors = rq->current_nr_sectors;
-	rq->buffer = NULL;
+	rq->buffer = bio_data(rq->bio);
 out:
 	return ret;
 }