raid5: remove a call to get_start_sect

The block layer always remaps partitions before calling into the
->make_request methods of drivers.  Thus the call to get_start_sect in
in_chunk_boundary will always return 0 and can be removed.
Reviewed-by: NShaohua Li <shli@fb.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

drivers/md/raid5.c

@@ -5092,10 +5092,12 @@ static int raid5_congested(struct mddev *mddev, int bits)
 static int in_chunk_boundary(struct mddev *mddev, struct bio *bio)
 {
 	struct r5conf *conf = mddev->private;
-	sector_t sector = bio->bi_iter.bi_sector + get_start_sect(bio->bi_bdev);
+	sector_t sector = bio->bi_iter.bi_sector;
 	unsigned int chunk_sectors;
 	unsigned int bio_sectors = bio_sectors(bio);
 
+	WARN_ON_ONCE(bio->bi_partno);
+
 	chunk_sectors = min(conf->chunk_sectors, conf->prev_chunk_sectors);
 	return  chunk_sectors >=
 		((sector & (chunk_sectors - 1)) + bio_sectors);