fsm: New device structure print

This change gives us simpler and better (IMO) organized structure:

<pre>
wicked: Device hierarchy structure:
wicked: lo
wicked: eth4
wicked: eth3
wicked: eth2
wicked: br42
wicked: +- masterdev -> bond0.42
wicked:      +- lowerdev -> bond0
wicked:             +- masterdev -> eth0
wicked:             +- masterdev -> eth1
wicked: +- masterdev -> dummy0
wicked: br73
wicked: +- masterdev -> bond0.73
wicked:      +- lowerdev -> bond0
wicked:             +- masterdev -> eth0
wicked:             +- masterdev -> eth1
wicked: +- masterdev -> dummy1
</pre>