Start uevent service handler from main thread

Start uevent service handler from main thread

We should start the uevent handler as early as possible so as
to not miss out any events. However, we cannot process these
events until after all paths have been discovered. So we
should be starting the uevent service routine only after
the discovery process.

Signed-off-by: Hannes Reinecke <hare@suse.de>