mtip32xx: fix dereference of stack garbage

We need to get the command payload from the request before
we attempt to dereference it.

Fixes: 4dda4735c581 ("mtip32xx: add a status field to struct mtip_cmd")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

drivers/block/mtip32xx/mtip32xx.c

@@ -4108,6 +4108,7 @@ static void mtip_no_dev_cleanup(struct request *rq, void *data, bool reserv)
 	struct mtip_cmd *cmd;
 
 	if (likely(!reserv)) {
+		cmd = blk_mq_rq_to_pdu(rq);
 		cmd->status = -ENODEV;
 		blk_mq_complete_request(rq);
 	} else if (test_bit(MTIP_PF_IC_ACTIVE_BIT, &dd->port->flags)) {