nodedev: Fix missing network devices

nodedev: Fix missing network devices

Commit id '8708ca01c' added a check to determine whether the NIC had
Switchdev capabilities; however, in doing so inadvertently would cause
network devices without a PCI device to not be added to the node device
database. Thus, network devices having a "computer" as a parent, such
as "net_lo*", "net_virbr*", "net_tun*", "net_vnet*", etc. were not added.

Alter the check to not even check for Switchdev bits if no PCI device found.