serial: pch_uart: 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: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/pch_uart.c

@@ -1853,7 +1853,6 @@ static void pch_uart_exit_port(struct eg20t_port *priv)
 		debugfs_remove(priv->debugfs);
 #endif
 	uart_remove_one_port(&pch_uart_driver, &priv->port);
-	pci_set_drvdata(priv->pdev, NULL);
 	free_page((unsigned long)priv->rxbuf.buf);
 }