block: drbd: drbd_receiver: Demote less than half complete kernel-doc header

Fixes the following W=1 kernel build warning(s):

 drivers/block/drbd/drbd_receiver.c:1641: warning: Function parameter or member 'op' not described in 'drbd_submit_peer_request'
 drivers/block/drbd/drbd_receiver.c:1641: warning: Function parameter or member 'op_flags' not described in 'drbd_submit_peer_request'
 drivers/block/drbd/drbd_receiver.c:1641: warning: Function parameter or member 'fault_type' not described in 'drbd_submit_peer_request'

Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Lars Ellenberg <lars.ellenberg@linbit.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: drbd-dev@lists.linbit.com
Cc: linux-block@vger.kernel.org
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20210312105530.2219008-10-lee.jones@linaro.orgSigned-off-by: NJens Axboe <axboe@kernel.dk>

drivers/block/drbd/drbd_receiver.c

@@ -1618,7 +1618,7 @@ static void drbd_issue_peer_wsame(struct drbd_device *device,
 }
 
 
-/**
+/*
  * drbd_submit_peer_request()
  * @device:	DRBD device.
  * @peer_req:	peer request