uuidd: don't truncate long socket paths

uuidd: don't truncate long socket paths

This was the error
  uuidd: couldn't bind unix socket /var/tmp/portage/sys-apps/util-linux-2.31.1/work/util-linux-2.31.1-abi_x86_64.amd64/tests/output/uuid/uuiddkOcTUuoZ7kaP3: Address already in use

because the socket path was truncated to 108 chars which was luckily
an existing directory.

Now we abort early with "uuidd: socket name too long: ... "

Reported-by: Thomas Deutschmann <whissi@gentoo.org>
Signed-off-by: Ruediger Meier <ruediger.meier@ga-group.nl>