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/security/cewl/default.nix

@@ -0,0 +1,33 @@
+{ stdenv, lib, fetchFromGitHub, bundlerEnv }:
+
+let
+  rubyEnv = bundlerEnv {
+    name = "cewl-ruby-env";
+    gemdir = ./.;
+  };
+in
+stdenv.mkDerivation rec {
+  pname = "cewl";
+  version = "5.5.2";
+  src = fetchFromGitHub {
+    owner = "digininja";
+    repo = "CeWL";
+    rev = version;
+    sha256 = "sha256-5LTZUr3OMeu1NODhIgBiVqtQnUWYfZTm73q61vT3rXc=";
+  };
+
+  buildInputs = [ rubyEnv.wrappedRuby ];
+
+  installPhase = ''
+    mkdir -p $out/bin
+    cp *.rb $out/bin/
+    mv $out/bin/cewl.rb $out/bin/cewl
+  '';
+
+  meta = with lib; {
+    description = "Custom wordlist generator";
+    homepage = "https://digi.ninja/projects/cewl.php/";
+    license = licenses.gpl3Plus;
+    maintainers = with maintainers; [ elohmeier ];
+  };
+}