Sjoerd Simons authored 6 years ago and Emanuele Aina committed 6 years ago

/etc/machine-id is expected to either contain a UUID or be *empty*.
using echo doesn't result in an empty file, it generates a file with
just a newline.

Switch to using truncate so it's actually an empty file. Fixes systemd
being unhappy about the content.

Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>