Fixed segment naming in topology tests
    
    As the segment name is a stochastic valu, which can have either of the two
    nodes as the left node, we need to adapt the tests to not expect some
    particular segment name but rather to calculate it dynamically based on node
    names and the output of topologysegment-find ipa call
    
    Reviewed-By: Martin Basti <mbasti@redhat.com>