Currently we use libuuid to print UUID only. This code is possible to replace
by one snprintf(). It seems better to duplicate this one snprintf than force
all distros to keep libuuid together with libblkid.
Note, this scenario has been already supported on --disable-libuuid.
Reported-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Karel Zak <kzak@redhat.com>