To check publishing of DNS information via DHCP, we need to extract a list
of nameservers and/or search domains from resolv.conf in the test script.
The current version (usually) leaves the result with a trailing ','.
That's usually ok because it happens on both guest and host sides. However
it's kind of confusing, and might stop working if the host had a
resolv.conf without a trailing \n on the last line. It also makes some
later changes we'll need more difficult.
So, normalize the output from resolv.conf a bit further, removing any
trailing ','. It turns out we can do this with a slightly less complex
sed expression than the one we already have.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>