usb: dwc2: Print error if unable to set DMA coherent mask

We better print an error in case probing of dwc2 fails on
setting the DMA coherent mask.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc2/platform.c

@@ -382,8 +382,10 @@ static int dwc2_driver_probe(struct platform_device *dev)
 	if (!dev->dev.dma_mask)
 		dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
 	retval = dma_set_coherent_mask(&dev->dev, DMA_BIT_MASK(32));
-	if (retval)
+	if (retval) {
+		dev_err(&dev->dev, "can't set coherent DMA mask: %d\n", retval);
 		return retval;
+	}
 
 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
 	hsotg->regs = devm_ioremap_resource(&dev->dev, res);