dmaengine: bcm-sba-raid: Pre-ack async tx descriptor

We should pre-ack async tx descriptor at time of
allocating sba_request (just like other RAID drivers).

Signed-off-by: Anup Patel <anup.patel@broadcom.com>
Reviewed-by: Ray Jui <ray.jui@broadcom.com>
Reviewed-by: Scott Branden <scott.branden@broadcom.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/bcm-sba-raid.c

@@ -237,6 +237,7 @@ static struct sba_request *sba_alloc_request(struct sba_device *sba)
 	atomic_set(&req->next_pending_count, 1);
 
 	dma_async_tx_descriptor_init(&req->tx, &sba->dma_chan);
+	async_tx_ack(&req->tx);
 
 	return req;
 }