CVE-2024-43875 PCI: endpoint: Clean up error handling in vpci_scan_bus()

In the Linux kernel, the following vulnerability has been resolved: PCI: endpoint: Clean up error handling in vpciscanbus Smatch complains about inconsistent NULL checking in vpciscanbus: drivers/pci/endpoint/functions/pci-epf-vntb.c:1024 vpciscanbus error: we previously assumed 'vpcibus' could b...