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/networking/maphosts/default.nix

@@ -0,0 +1,29 @@
+{ stdenv, lib, bundlerEnv, ruby, bundlerUpdateScript }:
+
+let
+  env = bundlerEnv {
+    name = "maphosts-gems";
+    inherit ruby;
+    gemdir = ./.;
+  };
+in stdenv.mkDerivation {
+  pname = "maphosts";
+  version = env.gems.maphosts.version;
+
+  dontUnpack = true;
+
+  installPhase = ''
+    mkdir -p "$out/bin"
+    ln -s "${env}/bin/maphosts" "$out/bin/maphosts"
+  '';
+
+  passthru.updateScript = bundlerUpdateScript "maphosts";
+
+  meta = with lib; {
+    description = "Small command line application for keeping your project hostnames in sync with /etc/hosts";
+    homepage    = "https://github.com/mpscholten/maphosts";
+    license     = licenses.mit;
+    maintainers = with maintainers; [ mpscholten nicknovitski ];
+    platforms   = platforms.all;
+  };
+}