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/development/tools/java/sawjap/default.nix

@@ -0,0 +1,28 @@
+{ stdenv, ocamlPackages }:
+
+let inherit (ocamlPackages) ocaml findlib sawja; in
+
+stdenv.mkDerivation {
+
+  pname = "sawjap";
+
+  inherit (sawja) src version;
+
+  prePatch = "cd test";
+
+  buildInputs = [ ocaml findlib sawja ];
+
+  buildPhase = ''
+    runHook preBuild
+    mkdir -p $out/bin
+    ocamlfind opt -o $out/bin/sawjap -package sawja -linkpkg sawjap.ml
+    runHook postBuild
+  '';
+
+  dontInstall = true;
+
+  meta = sawja.meta // {
+    description = "Pretty-print .class files";
+  };
+
+}