dmaengine: ti: k3-udma: Use PTR_ERR_OR_ZERO() to simplify code

Fixes coccicheck warnings:

drivers/dma/ti/k3-udma.c:1294:1-3: WARNING: PTR_ERR_OR_ZERO can be used
drivers/dma/ti/k3-udma.c:1311:1-3: WARNING: PTR_ERR_OR_ZERO can be used
drivers/dma/ti/k3-udma.c:1376:1-3: WARNING: PTR_ERR_OR_ZERO can be used
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Samuel Zou <zou_wei@huawei.com>
Link: https://lore.kernel.org/r/1588757146-38858-1-git-send-email-zou_wei@huawei.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/ti/k3-udma.c

@@ -1291,10 +1291,8 @@ static int udma_get_tchan(struct udma_chan *uc)
 	}
 
 	uc->tchan = __udma_reserve_tchan(ud, uc->config.channel_tpl, -1);
-	if (IS_ERR(uc->tchan))
-		return PTR_ERR(uc->tchan);
 
-	return 0;
+	return PTR_ERR_OR_ZERO(uc->tchan);
 }
 
 static int udma_get_rchan(struct udma_chan *uc)
@@ -1308,10 +1306,8 @@ static int udma_get_rchan(struct udma_chan *uc)
 	}
 
 	uc->rchan = __udma_reserve_rchan(ud, uc->config.channel_tpl, -1);
-	if (IS_ERR(uc->rchan))
-		return PTR_ERR(uc->rchan);
 
-	return 0;
+	return PTR_ERR_OR_ZERO(uc->rchan);
 }
 
 static int udma_get_chan_pair(struct udma_chan *uc)
@@ -1373,10 +1369,8 @@ static int udma_get_rflow(struct udma_chan *uc, int flow_id)
 	}
 
 	uc->rflow = __udma_get_rflow(ud, flow_id);
-	if (IS_ERR(uc->rflow))
-		return PTR_ERR(uc->rflow);
 
-	return 0;
+	return PTR_ERR_OR_ZERO(uc->rflow);
 }
 
 static void udma_put_rchan(struct udma_chan *uc)