virt/kvm/iommu.c: Add leading zeros to device's BDF notation in debug messages

When KVM (de)assigns PCI(e) devices to VMs, a debug message is printed
including the BDF notation of the respective device. Currently, the BDF
notation does not have the commonly used leading zeros. This produces
messages like "assign device 0:1:8.0", which look strange at first sight.

The patch fixes this by exchanging the printk(KERN_DEBUG ...) with dev_info()
and also inserts "kvm" into the debug message, so that it is obvious where
the message comes from. Also reduces LoC.

Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Andre Richter <andre.o.richter@gmail.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>

virt/kvm/iommu.c

@@ -190,11 +190,7 @@ int kvm_assign_device(struct kvm *kvm,
 
 	pdev->dev_flags |= PCI_DEV_FLAGS_ASSIGNED;
 
-	printk(KERN_DEBUG "assign device %x:%x:%x.%x\n",
-		assigned_dev->host_segnr,
-		assigned_dev->host_busnr,
-		PCI_SLOT(assigned_dev->host_devfn),
-		PCI_FUNC(assigned_dev->host_devfn));
+	dev_info(&pdev->dev, "kvm assign device\n");
 
 	return 0;
 out_unmap:
@@ -220,11 +216,7 @@ int kvm_deassign_device(struct kvm *kvm,
 
 	pdev->dev_flags &= ~PCI_DEV_FLAGS_ASSIGNED;
 
-	printk(KERN_DEBUG "deassign device %x:%x:%x.%x\n",
-		assigned_dev->host_segnr,
-		assigned_dev->host_busnr,
-		PCI_SLOT(assigned_dev->host_devfn),
-		PCI_FUNC(assigned_dev->host_devfn));
+	dev_info(&pdev->dev, "kvm deassign device\n");
 
 	return 0;
 }