Linking with libbtrfs fails because arg_strtou64 is not defined and we
cannot just add utils.o to library objects because it's not
library-clean.
Reported-by: Arvin Schnell <aschnell@suse.com>
Reported-by: Anton Farygin <rider@altlinux.org>
Signed-off-by: David Sterba <dsterba@suse.cz>
