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.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>