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/misc/cflow/default.nix

@@ -0,0 +1,51 @@
+{ lib, stdenv, fetchurl, gettext, emacs }:
+
+stdenv.mkDerivation rec {
+  pname = "cflow";
+  version = "1.7";
+
+  src = fetchurl {
+    url = "mirror://gnu/${pname}/${pname}-${version}.tar.bz2";
+    sha256 = "sha256-0BFGyvkAHiZhM0F8KoJYpktfwW/LCCoU9lKCBNDJcIY=";
+  };
+
+  patchPhase = ''
+    substituteInPlace "src/cflow.h"					\
+      --replace "/usr/bin/cpp"						\
+                "$(cat ${stdenv.cc}/nix-support/orig-cc)/bin/cpp"
+  '';
+
+  buildInputs = [ gettext ] ++
+    # We don't have Emacs/GTK/etc. on {Dar,Cyg}win.
+    lib.optional
+      (! (lib.lists.any (x: stdenv.hostPlatform.system == x)
+              [ "i686-cygwin" ]))
+      emacs;
+
+  doCheck = true;
+
+  meta = with lib; {
+    description = "Tool to analyze the control flow of C programs";
+
+    longDescription = ''
+      GNU cflow analyzes a collection of C source files and prints a
+      graph, charting control flow within the program.
+
+      GNU cflow is able to produce both direct and inverted flowgraphs
+      for C sources.  Optionally a cross-reference listing can be
+      generated.  Two output formats are implemented: POSIX and GNU
+      (extended).
+
+      The package also provides Emacs major mode for examining the
+      produced flowcharts in Emacs.
+    '';
+
+    license = licenses.gpl3Plus;
+
+    homepage = "https://www.gnu.org/software/cflow/";
+
+    maintainers = [ maintainers.vrthra ];
+
+    platforms = platforms.linux ++ platforms.darwin;
+  };
+}