dmaengine: xilinx_dma: fix xilinx_dma_child_probe() return documentation

Modify xilinx_dma_child_probe() return documentation to be inline
with implementation i.e. can also return failure value on error.
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
Link: https://lore.kernel.org/r/1666683737-7668-2-git-send-email-radhey.shyam.pandey@amd.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/xilinx/xilinx_dma.c

@@ -2924,7 +2924,7 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
  * @xdev: Driver specific device structure
  * @node: Device node
  *
- * Return: 0 always.
+ * Return: '0' on success and failure value on error.
  */
 static int xilinx_dma_child_probe(struct xilinx_dma_device *xdev,
 				    struct device_node *node)