uboot: (firmwareOdroidC2/C4) don't invoke patch tool, use patches = [] instead

https://github.com/NixOS/nixpkgs/blob/master/pkgs/stdenv/generic/setup.sh#L948
this can do it nicely.

Signed-off-by: Anton Arapov <anton@deadbeef.mx>

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

@@ -0,0 +1,29 @@
+{ lib, stdenv, fetchFromGitHub, pam, bison, flex, autoreconfHook }:
+
+stdenv.mkDerivation rec {
+  pname = "libcgroup";
+  version = "0.42.2";
+
+  src = fetchFromGitHub {
+    owner = pname;
+    repo = pname;
+    rev = "v${version}";
+    sha256 = "1h8s70lm6g7r0wj7j3xgj2g3j9fifvsy2pna6w0j3i5hh42qfms4";
+  };
+
+  buildInputs = [ pam bison flex ];
+  nativeBuildInputs = [ autoreconfHook ];
+
+  postPatch = ''
+    substituteInPlace src/tools/Makefile.am \
+      --replace 'chmod u+s' 'chmod +x'
+  '';
+
+  meta = {
+    description = "Library and tools to manage Linux cgroups";
+    homepage    = "http://libcg.sourceforge.net/";
+    license     = lib.licenses.lgpl2;
+    platforms   = lib.platforms.linux;
+    maintainers = [ lib.maintainers.thoughtpolice ];
+  };
+}