iommu/amd: Use pci_dev_id() helper

Use new helper pci_dev_id() to simplify the code.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/amd_iommu.c

@@ -165,7 +165,7 @@ static inline u16 get_pci_device_id(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
 
-	return PCI_DEVID(pdev->bus->number, pdev->devfn);
+	return pci_dev_id(pdev);
 }
 
 static inline int get_acpihid_device_id(struct device *dev,