Commit id '
c4a4603de' added an output <path> to the nodedev xml, but
did not update the schema.
This resulted in the failure of the 'virt-xml-validate' on a file
generated by 'virsh nodedev-dumpxml pci_0000_00_00_0' (for example).
This was found/seen by running autotest on my host.
<!-- The name of the network, used to refer to it through the API
and in virsh -->
<element name="name"><text/></element>
+ <optional>
+ <element name="path"><text/></element>
+ </optional>
<optional>
<element name="parent"><text/></element>
</optional>