Single-node DVR install confuses easyOVS

[Brian Haley]

I know the DVR support is experimental, but I have found a bug in it.

If you have a single-node DVR system, something that's simple to do with devstack by using Q_DVR_MODE=dvr_snat in local.conf, running easyOVS 'dvr' command complains about finding an 'rfp' interface in the qrouter namespace. This is perfectly valid in this single-node config. Running 'dvr check compute' does run OK so the code just needs a little tweaking to detect this correctly.

[Baohua Yang]

Thanks for the reporting!
Currently it does not supports single-node topology.
Will add it to know issues.