usb: gadget: at91_udc: use devm_platform_ioremap_resource() to simplify code

Use devm_platform_ioremap_resource() to simplify the code a bit.
This is detected by coccinelle.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20190904090239.23920-1-yuehaibing@huawei.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/udc/at91_udc.c

@@ -1808,7 +1808,6 @@ static int at91udc_probe(struct platform_device *pdev)
 	struct device	*dev = &pdev->dev;
 	struct at91_udc	*udc;
 	int		retval;
-	struct resource	*res;
 	struct at91_ep	*ep;
 	int		i;
 
@@ -1839,8 +1838,7 @@ static int at91udc_probe(struct platform_device *pdev)
 			ep->is_pingpong = 1;
 	}
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	udc->udp_baseaddr = devm_ioremap_resource(dev, res);
+	udc->udp_baseaddr = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(udc->udp_baseaddr))
 		return PTR_ERR(udc->udp_baseaddr);