netlink: message format descriptions for genetlink control

For the sake of completeness, add description of genetlink message formats
of GENL_ID_CTRL family. We use this to get the id of "ethtool" genetlink
family and "monitor" multicast group.

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
3 files changed