criu: 3.8 -> 3.8.1

Semi-automatic update generated by https://github.com/ryantm/nixpkgs-update tools.

This update was made based on information from https://repology.org/metapackage/criu/versions.

These checks were done:

- built on NixOS
- ran `/nix/store/yqfshz1c0qp2h8vdcswiaknxb6ibxfsl-criu-3.8.1/bin/compel -h` got 0 exit code
- ran `/nix/store/yqfshz1c0qp2h8vdcswiaknxb6ibxfsl-criu-3.8.1/bin/compel --help` got 0 exit code
- ran `/nix/store/yqfshz1c0qp2h8vdcswiaknxb6ibxfsl-criu-3.8.1/bin/criu -h` got 0 exit code
- ran `/nix/store/yqfshz1c0qp2h8vdcswiaknxb6ibxfsl-criu-3.8.1/bin/criu --help` got 0 exit code
- ran `/nix/store/yqfshz1c0qp2h8vdcswiaknxb6ibxfsl-criu-3.8.1/bin/criu -V` and found version 3.8.1
- ran `/nix/store/yqfshz1c0qp2h8vdcswiaknxb6ibxfsl-criu-3.8.1/bin/criu --version` and found version 3.8.1
- found 3.8.1 with grep in /nix/store/yqfshz1c0qp2h8vdcswiaknxb6ibxfsl-criu-3.8.1
- directory tree listing: https://gist.github.com/4324a1815464a7da41c4b8cd5056b1b7

pkgs/os-specific/linux/criu/default.nix

@@ -4,11 +4,11 @@
 
 stdenv.mkDerivation rec {
   name    = "criu-${version}";
-  version = "3.8";
+  version = "3.8.1";
 
   src = fetchurl {
     url    = "http://download.openvz.org/criu/${name}.tar.bz2";
-    sha256 = "0gmvbnb5wa3f4nzam7gssclfai8g5363dhp8qc7q32dcx4wxbgam";
+    sha256 = "0csyhsc5d6wkcjyvsp6h9x8zxn3zk574s84gfmy3gjagv3nwqd51";
   };
 
   enableParallelBuilding = true;