Rules don't have unique identifiers, so all attributes are compared
by initializing the ID mask to ~0. This doesn't work however since
nl_object_identical verifies whether the ID attributes are actually
present before comparing the objects, which is never the case.
Work around by using the intersection of present attributes when
comparing two rule objects.
Signed-off-by: Patrick McHardy <kaber@trash.net>
3c28aa5dca