Reboot command called with full path, part 2

OpenSuSE doesn't have /sbin in default user's PATH. Therefore
we can fix a reboot problem with always calling reboot with
its full path.

Change-Id: I99c2637e50a04e56099d1bb2e242bf4d6f8c9291
Reviewed-by: Heikki Halmet <heikki.halmet@digia.com>