node_device_udev: Pass the `udevEventData` via parameter and use refcounting

node_device_udev: Pass the `udevEventData` via parameter and use refcounting

Instead of accessing the global `driver` object pass the `udevEventData` as
parameter to the thread handler and watch callback. This has the advantage that:
1. proper refcounting
2. easier to read and test

Reviewed-by: Jonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>