usb: dwc3: omap: Fix devm_regulator_get_optional() error handling

Commit 533561a ("usb: dwc3: omap: Use
devm_regulator_get_optional()") assumed NULL was returned, but
devm_regulator_get_optional() returns -ENODEV rather than NULL like
other *_get_optional() functions.

Fixes: 533561a ("usb: dwc3: omap: Use devm_regulator_get_optional()")
Signed-off-by: Rob Herring (Arm) <[email protected]>
Acked-by: Thinh Nguyen <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: robherring

drivers/usb/dwc3/dwc3-omap.c

@@ -484,8 +484,11 @@ static int dwc3_omap_probe(struct platform_device *pdev)
 		return PTR_ERR(base);
 
 	vbus_reg = devm_regulator_get_optional(dev, "vbus");
-	if (IS_ERR(vbus_reg))
-		return dev_err_probe(dev, PTR_ERR(vbus_reg), "vbus init failed\n");
+	if (IS_ERR(vbus_reg)) {
+		if (PTR_ERR(vbus_reg) != -ENODEV)
+			return dev_err_probe(dev, PTR_ERR(vbus_reg), "vbus init failed\n");
+		vbus_reg = NULL;
+	}
 
 	omap->dev	= dev;
 	omap->irq	= irq;