Remove remaining references to Upstart

nixos/modules/virtualisation/ec2-data.nix

@@ -1,5 +1,5 @@
-# This module defines an Upstart job that obtains the SSH key and host
-# name of virtual machines running on Amazon EC2, Eucalyptus and
+# This module defines a systemd service that obtains the SSH key and
+# host name of virtual machines running on Amazon EC2, Eucalyptus and
 # OpenStack Compute (Nova).
 
 { config, pkgs, ... }:

nixos/modules/virtualisation/libvirtd.nix

@@ -1,4 +1,4 @@
-# Upstart jobs for libvirtd.
+# Systemd services for libvirtd.
 
 { config, pkgs, ... }:
 
@@ -122,9 +122,6 @@ in
         wants = [ "libvirtd.service" ];
         after = [ "libvirtd.service" ];
 
-        # We want to suspend VMs only on shutdown, but Upstart is broken.
-        #stopOn = "";
-
         restartIfChanged = false;
 
         path = [ pkgs.gettext pkgs.libvirt pkgs.gawk ];