net: marvell: prestera: use dev_driver_string() instead of pci_dev->driver->name

Replace dev->driver_name() by dev_driver_string() for the corresponding
struct device.  This is a step toward removing pci_dev->driver.

[bhelgaas: split to separate patch]
Link: https://lore.kernel.org/r/20211004125935.2300113-8-u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/net/ethernet/marvell/prestera/prestera_pci.c

@@ -720,7 +720,7 @@ static int prestera_fw_load(struct prestera_fw *fw)
 static int prestera_pci_probe(struct pci_dev *pdev,
 			      const struct pci_device_id *id)
 {
-	const char *driver_name = pdev->driver->name;
+	const char *driver_name = dev_driver_string(&pdev->dev);
 	struct prestera_fw *fw;
 	int err;