usb: gadget: udc-core: remove protection when setting gadget.dev.release

now that no UDC driver touches gadget.dev.release
we can assign our release function to it without
being afraid of breaking anything.
Signed-off-by: NFelipe Balbi <balbi@ti.com>

drivers/usb/gadget/udc-core.c

@@ -198,12 +198,10 @@ int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
 	gadget->dev.dma_parms = parent->dma_parms;
 	gadget->dev.dma_mask = parent->dma_mask;
 
-	if (release) {
+	if (release)
 		gadget->dev.release = release;
-	} else {
-		if (!gadget->dev.release)
-			gadget->dev.release = usb_udc_nop_release;
-	}
+	else
+		gadget->dev.release = usb_udc_nop_release;
 
 	ret = device_register(&gadget->dev);
 	if (ret)