ublk: get ubq from pdu in ublk_cmd_list_tw_cb()

Save a few pointer dereferences by obtaining struct ublk_queue *ubq from
the ublk_uring_cmd_pdu instead of the request's mq_hctx.

Signed-off-by: Caleb Sander Mateos <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

Author: calebsander

drivers/block/ublk_drv.c

@@ -1287,7 +1287,7 @@ static void ublk_cmd_list_tw_cb(struct io_uring_cmd *cmd,
 {
 	struct ublk_uring_cmd_pdu *pdu = ublk_get_uring_cmd_pdu(cmd);
 	struct request *rq = pdu->req_list;
-	struct ublk_queue *ubq = rq->mq_hctx->driver_data;
+	struct ublk_queue *ubq = pdu->ubq;
 	struct request *next;
 
 	do {