usb: gadget: remove redundant self assignment

The assignment ret = ret is redundant and can be removed.

Reviewed-by: Krzysztof Opasiak <[e-mail]>
Reviewed-by: Peter Chen <[e-mail]>
Signed-off-by: Stefan Agner <[e-mail]>
Signed-off-by: Felipe Balbi <[e-mail]>

drivers/usb/gadget/udc/core.c

···
 		goto out;
 
 	ret = ep->ops->disable(ep);
-	if (ret) {
-		ret = ret;
+	if (ret)
 		goto out;
-	}
 
 	ep->enabled = false;