criu: scripts: remove criu service files

As it is not recomended to run criu as a root system service, lets
remove service file to stop encouraging people to do it.
Signed-off-by: Ruslan Kuprieiev <rkuprieiev@cloudlinux.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

scripts/sd/criu.service

-[Unit]
-Description=Checkpoint Restore in Userspace daemon
-
-[Service]
-ExecStart=/usr/sbin/criu service -o /var/log/criu-service.log
-
-[Install]
-WantedBy=multi-user.target

scripts/sd/criu.socket

-[Unit]
-Description=Checkpoint Restore in Userspace socket
-
-[Socket]
-ListenSequentialPacket=/var/run/criu-service.socket
-
-[Install]
-WantedBy=sockets.target