net: ravb: Fix registered interrupt names

As interrupts are now requested from ravb_probe(), before calling
register_netdev(), ndev->name still contains the template "eth%d",
leading to funny names in /proc/interrupts.  E.g. on R-Car E3:

	89:  0      0  GICv2  93 Level  eth%d:ch22:multi
	90:  0      3  GICv2  95 Level  eth%d:ch24:emac
	91:  0  23484  GICv2  71 Level  eth%d:ch0:rx_be
	92:  0      0  GICv2  72 Level  eth%d:ch1:rx_nc
	93:  0  13735  GICv2  89 Level  eth%d:ch18:tx_be
	94:  0      0  GICv2  90 Level  eth%d:ch19:tx_nc

Worse, on platforms with multiple RAVB instances (e.g. R-Car V4H), all
interrupts have similar names.

Fix this by using the device name instead, like is done in several other
drivers:

	89:  0      0  GICv2  93 Level  e6800000.ethernet:ch22:multi
	90:  0      1  GICv2  95 Level  e6800000.ethernet:ch24:emac
	91:  0  28578  GICv2  71 Level  e6800000.ethernet:ch0:rx_be
	92:  0      0  GICv2  72 Level  e6800000.ethernet:ch1:rx_nc
	93:  0  14044  GICv2  89 Level  e6800000.ethernet:ch18:tx_be
	94:  0      0  GICv2  90 Level  e6800000.ethernet:ch19:tx_nc

Rename the local variable dev_name, as it shadows the dev_name()
function, and pre-initialize it, to simplify the code.

Fixes: 32f012b8 ("net: ravb: Move getting/requesting IRQs in the probe() method")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Reviewed-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Tested-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> # on RZ/G3S
Link: https://lore.kernel.org/r/cde67b68adf115b3cf0b44c32334ae00b2fbb321.1713944647.git.geert+renesas@glider.beSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/renesas/ravb_main.c

@@ -2722,19 +2722,18 @@ static int ravb_setup_irq(struct ravb_private *priv, const char *irq_name,
 	struct platform_device *pdev = priv->pdev;
 	struct net_device *ndev = priv->ndev;
 	struct device *dev = &pdev->dev;
-	const char *dev_name;
+	const char *devname = dev_name(dev);
 	unsigned long flags;
 	int error, irq_num;
 
 	if (irq_name) {
-		dev_name = devm_kasprintf(dev, GFP_KERNEL, "%s:%s", ndev->name, ch);
-		if (!dev_name)
+		devname = devm_kasprintf(dev, GFP_KERNEL, "%s:%s", devname, ch);
+		if (!devname)
 			return -ENOMEM;
 
 		irq_num = platform_get_irq_byname(pdev, irq_name);
 		flags = 0;
 	} else {
-		dev_name = ndev->name;
 		irq_num = platform_get_irq(pdev, 0);
 		flags = IRQF_SHARED;
 	}
@@ -2744,9 +2743,9 @@ static int ravb_setup_irq(struct ravb_private *priv, const char *irq_name,
 	if (irq)
 		*irq = irq_num;
 
-	error = devm_request_irq(dev, irq_num, handler, flags, dev_name, ndev);
+	error = devm_request_irq(dev, irq_num, handler, flags, devname, ndev);
 	if (error)
-		netdev_err(ndev, "cannot request IRQ %s\n", dev_name);
+		netdev_err(ndev, "cannot request IRQ %s\n", devname);
 
 	return error;
 }