iommu/vt-d: Use dev_is_pci() to check whether it is pci device

Use PCI standard marco dev_is_pci() instead of directly compare
pci_bus_type to check whether it is pci device.

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 43b9bfe..64d8942 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -2758,7 +2758,7 @@
 	struct pci_dev *pdev;
 	int found;
 
-	if (unlikely(dev->bus != &pci_bus_type))
+	if (unlikely(!dev_is_pci(dev)))
 		return 1;
 
 	pdev = to_pci_dev(dev);