usb: gadget: fsl: Fix unsigned expression compared with zero in fsl_udc_probe

udc_controller->irq is "unsigned int" always >= 0, but platform_get_irq may
return little than zero. So "dc_controller->irq < 0" condition is never
accessible.
Acked-by: Li Yang <leoyang.li@nxp.com>
Signed-off-by: Ye Bin <yebin10@huawei.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

drivers/usb/gadget/udc/fsl_udc_core.c

@@ -2439,11 +2439,12 @@ static int fsl_udc_probe(struct platform_device *pdev)
 	/* DEN is bidirectional ep number, max_ep doubles the number */
 	udc_controller->max_ep = (dccparams & DCCPARAMS_DEN_MASK) * 2;
 
-	udc_controller->irq = platform_get_irq(pdev, 0);
-	if (udc_controller->irq <= 0) {
-		ret = udc_controller->irq ? : -ENODEV;
+	ret = platform_get_irq(pdev, 0);
+	if (ret <= 0) {
+		ret = ret ? : -ENODEV;
 		goto err_iounmap;
 	}
+	udc_controller->irq = ret;
 
 	ret = request_irq(udc_controller->irq, fsl_udc_irq, IRQF_SHARED,
 			driver_name, udc_controller);