tests: Convert over to using converged to test for ospf being converged

tests: Convert over to using converged to test for ospf being converged

OSPF when it is deciding on whom it should elect for DR and backup
has a process that prioritizes network stabilty over the exact
same results of who is the DR / Backups.

Essentially if we have r1 ----- r2

Let's say r1 has a higher priority, but r2 comes up first, starts
sending hello packets and then decides that it is the DR.  At some
point in time in the future, r1 comes up and then connects to r2
at that point it sees that r2 has elected itself DR and it keeps
it that way.

This is by design of the system.  With our tight ospf timers as
well as high load being experienced on our test systems.  There
exists a bunch of ospf tests that we cannot guarantee that a
consistent DR will be elected for the test.  As such let's not
even pretend that we care a bunch and just look for `Full`.
If we care about `ordering` we need to spend more time getting
the tests to actually start routers, ensure that htey are up and
running in the right order so that priority can take place.

Signed-off-by: Donald Sharp <sharpd@nvidia.com>