i2c: designware: use to_pci_dev()

Use to_pci_dev() instead of open-coding it.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
diff --git a/drivers/i2c/busses/i2c-designware-pcidrv.c b/drivers/i2c/busses/i2c-designware-pcidrv.c
index 1543d35d..7368be0 100644
--- a/drivers/i2c/busses/i2c-designware-pcidrv.c
+++ b/drivers/i2c/busses/i2c-designware-pcidrv.c
@@ -162,7 +162,7 @@
 #ifdef CONFIG_PM
 static int i2c_dw_pci_suspend(struct device *dev)
 {
-	struct pci_dev *pdev = container_of(dev, struct pci_dev, dev);
+	struct pci_dev *pdev = to_pci_dev(dev);
 
 	i2c_dw_disable(pci_get_drvdata(pdev));
 	return 0;
@@ -170,7 +170,7 @@
 
 static int i2c_dw_pci_resume(struct device *dev)
 {
-	struct pci_dev *pdev = container_of(dev, struct pci_dev, dev);
+	struct pci_dev *pdev = to_pci_dev(dev);
 
 	return i2c_dw_init(pci_get_drvdata(pdev));
 }