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/tools/graphics/mscgen/default.nix

@@ -0,0 +1,53 @@
+{ lib, stdenv
+, bison
+, fetchurl
+, flex
+, gd
+, libjpeg
+, libpng
+, libwebp
+, pkg-config
+, runtimeShell
+, zlib
+}:
+
+stdenv.mkDerivation rec {
+  pname = "mscgen";
+  version = "0.20";
+
+  src = fetchurl {
+    url = "http://www.mcternan.me.uk/mscgen/software/mscgen-src-${version}.tar.gz";
+    sha256 = "3c3481ae0599e1c2d30b7ed54ab45249127533ab2f20e768a0ae58d8551ddc23";
+  };
+
+  nativeBuildInputs = [ bison flex pkg-config ];
+  buildInputs = [ gd libjpeg libpng libwebp zlib ];
+
+  doCheck = true;
+  preCheck = ''
+    sed -i -e "s|#!/bin/bash|#!${runtimeShell}|" test/renderercheck.sh
+  '';
+
+  outputs = [ "out" "man" ];
+
+  meta = {
+    homepage = "http://www.mcternan.me.uk/mscgen/";
+    description = "Convert Message Sequence Chart descriptions into PNG, SVG, or EPS images";
+    license = lib.licenses.gpl2;
+
+    longDescription = ''
+      Mscgen is a small program that parses Message Sequence Chart
+      descriptions and produces PNG, SVG, EPS or server side image maps
+      (ismaps) as the output. Message Sequence Charts (MSCs) are a way
+      of representing entities and interactions over some time period
+      and are often used in combination with SDL. MSCs are popular in
+      Telecoms to specify how protocols operate although MSCs need not
+      be complicated to create or use. Mscgen aims to provide a simple
+      text language that is clear to create, edit and understand, which
+      can also be transformed into common image formats for display or
+      printing.
+    '';
+
+    platforms = lib.platforms.unix;
+  };
+}