serial: txx9: remove unnecessary pci_set_drvdata()

The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/serial_txx9.c

@@ -1220,8 +1220,6 @@ static void pciserial_txx9_remove_one(struct pci_dev *dev)
 {
 	struct uart_txx9_port *up = pci_get_drvdata(dev);
 
-	pci_set_drvdata(dev, NULL);
-
 	if (up) {
 		serial_txx9_unregister_port(up->port.line);
 		pci_disable_device(dev);