drbd: Add peer_device to Kernel doc

Add missing documentation of peer_device parameter to Kernel doc.

These parameters were added in commit 8164dd6c ("drbd: Add peer
device parameter to whole-bitmap I/O handlers")

Flagged by W=1 builds.
Signed-off-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240723-drbd-doc-v1-1-a04d9b7a9688@kernel.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/drbd/drbd_main.c

@@ -3422,6 +3422,7 @@ void drbd_uuid_set_bm(struct drbd_device *device, u64 val) __must_hold(local)
 /**
  * drbd_bmio_set_n_write() - io_fn for drbd_queue_bitmap_io() or drbd_bitmap_io()
  * @device:	DRBD device.
+ * @peer_device: Peer DRBD device.
  *
  * Sets all bits in the bitmap and writes the whole bitmap to stable storage.
  */
@@ -3448,6 +3449,7 @@ int drbd_bmio_set_n_write(struct drbd_device *device,
 /**
  * drbd_bmio_clear_n_write() - io_fn for drbd_queue_bitmap_io() or drbd_bitmap_io()
  * @device:	DRBD device.
+ * @peer_device: Peer DRBD device.
  *
  * Clears all bits in the bitmap and writes the whole bitmap to stable storage.
  */
@@ -3501,6 +3503,7 @@ static int w_bitmap_io(struct drbd_work *w, int unused)
  * @done:	callback to be called after the bitmap IO was performed
  * @why:	Descriptive text of the reason for doing the IO
  * @flags:	Bitmap flags
+ * @peer_device: Peer DRBD device.
  *
  * While IO on the bitmap happens we freeze application IO thus we ensure
  * that drbd_set_out_of_sync() can not be called. This function MAY ONLY be
@@ -3549,6 +3552,7 @@ void drbd_queue_bitmap_io(struct drbd_device *device,
  * @io_fn:	IO callback to be called when bitmap IO is possible
  * @why:	Descriptive text of the reason for doing the IO
  * @flags:	Bitmap flags
+ * @peer_device: Peer DRBD device.
  *
  * freezes application IO while that the actual IO operations runs. This
  * functions MAY NOT be called from worker context.