Fix LXC/LXD and machined detection for cgroups v2

The second field is always blank in cgroups v2 unlike v1, adjust parsing to
support both cases for LXC/LXD and machined. This is the same fix as previously
made for Docker in liske#234.

Example: 0::/lxc.payload.focal/system.slice/avahi-daemon.service

perl/lib/NeedRestart/CONT/LXC.pm

@@ -81,7 +81,7 @@ sub check {
  }
 
  # look for LXC cgroups
- return unless($cg =~ /^\d+:[^:]+:\/lxc(?:.payload)?[.\/]([^\/\n]+)($|\/)/m);
+ return unless($cg =~ /^\d+:[^:]*:\/lxc(?:.payload)?[.\/]([^\/\n]+)($|\/)/m);
 
  my $name = $1;
  my $type = ($self->{has_lxd} && -d qq($self->{lxd_container_path}/$name) ? 'LXD' : 'LXC');

perl/lib/NeedRestart/CONT/machined.pm

@@ -68,7 +68,7 @@ sub check {
  }
 
  # look for machined cgroups
- return 0 unless($cg =~ /^\d+:[^:]+:\/machine.slice\/machine-(.+)\.scope$/m);
+ return 0 unless($cg =~ /^\d+:[^:]*:\/machine.slice\/machine-(.+)\.scope$/m);
 
  my $name = $1;
  unless($norestart) {