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/filesystems/genext2fs/default.nix

@@ -0,0 +1,25 @@
+{ lib, stdenv, fetchurl }:
+
+stdenv.mkDerivation rec {
+  pname = "genext2fs";
+  version = "1.4.1";
+
+  src = fetchurl {
+    url = "mirror://sourceforge/genext2fs/genext2fs-${version}.tar.gz";
+    sha256 = "1z7czvsf3ircvz2cw1cf53yifsq29ljxmj15hbgc79l6gbxbnka0";
+  };
+
+  # https://sourceforge.net/p/genext2fs/bugs/2/
+  # Will be fixed in the next release, whenever this happens
+  postPatch = ''
+    sed -e 's@4 [*] (EXT2_TIND_BLOCK+1)@-1+&@' -i genext2fs.c
+  '';
+
+  meta = with lib; {
+    homepage = "http://genext2fs.sourceforge.net/";
+    description = "A tool to generate ext2 filesystem images without requiring root privileges";
+    license = licenses.gpl2;
+    platforms = platforms.all;
+    maintainers = [ maintainers.bjornfor ];
+  };
+}