netinfoTests: fix link info consistency and docstrings

Change-Id: I2ae7289ebef4cb714f2c4ad2e541fc4580cfff48
Signed-off-by: Antoni S. Puimedon <asegurap@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/21564
Reviewed-by: Dan Kenigsberg <danken@redhat.com>