serial: 8250: Use dev_get_drvdata where possible

Instead of using to_pci_dev + pci_get_drvdata,
use dev_get_drvdata to make code simpler.
Signed-off-by: NChuhong Yuan <hslester96@gmail.com>
Link: https://lore.kernel.org/r/20190724131758.1764-1-hslester96@gmail.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/8250/8250_exar.c

@@ -561,8 +561,7 @@ static int __maybe_unused exar_suspend(struct device *dev)
 
 static int __maybe_unused exar_resume(struct device *dev)
 {
-	struct pci_dev *pcidev = to_pci_dev(dev);
-	struct exar8250 *priv = pci_get_drvdata(pcidev);
+	struct exar8250 *priv = dev_get_drvdata(dev);
 	unsigned int i;
 
 	for (i = 0; i < priv->nr; i++)

drivers/tty/serial/8250/8250_pci.c

@@ -3859,8 +3859,7 @@ static void pciserial_remove_one(struct pci_dev *dev)
 #ifdef CONFIG_PM_SLEEP
 static int pciserial_suspend_one(struct device *dev)
 {
-	struct pci_dev *pdev = to_pci_dev(dev);
-	struct serial_private *priv = pci_get_drvdata(pdev);
+	struct serial_private *priv = dev_get_drvdata(dev);
 
 	if (priv)
 		pciserial_suspend_ports(priv);