drbd: don't detour through bd_contains for the gendisk

bd_disk is set on all block devices, including those for partitions.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

drivers/block/drbd/drbd_receiver.c

@@ -2789,7 +2789,7 @@ bool drbd_rs_should_slow_down(struct drbd_device *device, sector_t sector,
 
 bool drbd_rs_c_min_rate_throttle(struct drbd_device *device)
 {
-	struct gendisk *disk = device->ldev->backing_bdev->bd_contains->bd_disk;
+	struct gendisk *disk = device->ldev->backing_bdev->bd_disk;
 	unsigned long db, dt, dbdt;
 	unsigned int c_min_rate;
 	int curr_events;

drivers/block/drbd/drbd_worker.c

@@ -1672,7 +1672,7 @@ void drbd_resync_after_changed(struct drbd_device *device)
 
 void drbd_rs_controller_reset(struct drbd_device *device)
 {
-	struct gendisk *disk = device->ldev->backing_bdev->bd_contains->bd_disk;
+	struct gendisk *disk = device->ldev->backing_bdev->bd_disk;
 	struct fifo_buffer *plan;
 
 	atomic_set(&device->rs_sect_in, 0);