usb: gadget: udc: fix free_irq() after request_irq() failed

My static checker detected the mistake. I fix this by changing "goto
err_irq" to "goto err_req". The label err_irq is not used now
so this patch also removes it.

Signed-off-by: Takeshi Yoshimura <[e-mail]>
Signed-off-by: Felipe Balbi <[e-mail]>

drivers/usb/gadget/udc/fotg210-udc.c

···
 			  udc_name, fotg210);
 	if (ret < 0) {
 		pr_err("request_irq error (%d)\n", ret);
-		goto err_irq;
+		goto err_req;
 	}
 
 	ret = usb_add_gadget_udc(&pdev->dev, &fotg210->gadget);
···
 	return 0;
 
 err_add_udc:
-err_irq:
 	free_irq(ires->start, fotg210);
 
 err_req: