pci: show id info when pci BDF conflict

pci: show id info when pci BDF conflict

During qemu init stage, when there is pci BDF conflicts, qemu print
a warning but not showing which device the BDF is occupied by. E.x:

"PCI: slot 2 function 0 not available for virtio-scsi-pci, in use by virtio-scsi-pci"

To facilitate user knowing the offending device and fixing it, showing
the id info in the warning.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Message-Id: <20220223094435.64495-1-zhenzhong.duan@intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>