Fix the error logging of the promhttp handler by connecting it to the
promlog setup.
* Switch to go-kit/log.
* Cleanup CHANGELOG.
Fixes: https://github.com/prometheus/node_exporter/issues/1886
Signed-off-by: Ben Kochie <superq@gmail.com>
* Use `device` label to match other `node_network_...` metics.
* Fix naming convention to match Promehteus best practices.
Signed-off-by: Ben Kochie <superq@gmail.com>
