xen-pciback: simplify vpci's find hook

There's no point in comparing SBDF - we can simply compare the struct
pci_dev pointers. If they weren't the same for a given device, we'd have
bigger problems from having stored a stale pointer.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

Link: https://lore.kernel.org/r/158273a2-d1b9-3545-b25d-affca867376c@suse.comSigned-off-by: Juergen Gross <jgross@suse.com>

drivers/xen/xen-pciback/vpci.c

@@ -233,7 +233,6 @@ static int __xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
 					unsigned int *devfn)
 {
 	struct pci_dev_entry *entry;
-	struct pci_dev *dev = NULL;
 	struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
 	int found = 0, slot;
 
@@ -242,11 +241,7 @@ static int __xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
 		list_for_each_entry(entry,
 			    &vpci_dev->dev_list[slot],
 			    list) {
-			dev = entry->dev;
-			if (dev && dev->bus->number == pcidev->bus->number
-				&& pci_domain_nr(dev->bus) ==
-					pci_domain_nr(pcidev->bus)
-				&& dev->devfn == pcidev->devfn) {
+			if (entry->dev == pcidev) {
 				found = 1;
 				*domain = 0;
 				*bus = 0;