collectd: Fix collectd / Luci statistics breakage due to r39119 / #15010

collectd: Fix collectd / Luci statistics breakage due to r39119 / #15010

Collectd / Luci statistics module has been broken since r39119 (in December
2013). Buildbot has not built it succesfully since then.

Bug 15010 describes the issue:  https://dev.openwrt.org/ticket/15010
Changeset 39119:  https://dev.openwrt.org/changeset/39119

The build breakage only concerns one collectd plugin, netlink, which expects
iproute2 to be compiled with "fpic" option, which was removed by r39119 in
order to make iproute2 smaller.
http://buildbot.openwrt.org:8010/broken_packages/ar71xx/collectd/compile.txt

There are two alternative fixes:
- add fpic back to iproute2 compile options. But devs apparently
intentionally removed it to decrease size
- alternatively, disable netlink plugin in collectd by marking it broken

It is unfortunate that the whole collectd remains uncompiled in buildbot
snapshots due to that one minor plugin. Other bugs related to this (e.g.
#15077 and #14642) were closed three weeks ago as duplicates of #15010, but I
have seen no action regarding actually fixing the issue.

So, please find attached a patch marking the netlink plugin broken.
All other collectd modules do compile. I compile-tested them with ar71xx.

Signed-off-by: hannu.nyman@iki.fi
git-svn-id: svn://svn.openwrt.org/openwrt/packages@40645 3c298f89-4303-0410-b956-a3cf2f4a3e73