If the interface goes into failure state (is disconnecting)
then with this change one hotplug.d event is generated.

The same is true for the recovery state (is connecting), when the interface
comes back from a failure state.

In both cases, a hotplug.d event for the iface is triggered. Once
with the $ACTION=disconnecting and once for the $ACTION=connecting.

Signed-off-by: Florian Eckert <fe@dev.tdt.de>