usb: gadget: s3c-hsotg: fix PHY error handling

PHY laye rno longer return NULL. We need to
switch over from IS_ERR_OR_NULL() to IS_ERR().

Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/gadget/s3c-hsotg.c b/drivers/usb/gadget/s3c-hsotg.c
index f1ceabf..a3cdc32 100644
--- a/drivers/usb/gadget/s3c-hsotg.c
+++ b/drivers/usb/gadget/s3c-hsotg.c
@@ -3467,7 +3467,7 @@
 	}
 
 	phy = devm_usb_get_phy(dev, USB_PHY_TYPE_USB2);
-	if (IS_ERR_OR_NULL(phy)) {
+	if (IS_ERR(phy)) {
 		/* Fallback for pdata */
 		plat = pdev->dev.platform_data;
 		if (!plat) {