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/servers/varnish/digest.nix

@@ -0,0 +1,33 @@
+{ lib, stdenv, fetchFromGitHub, autoreconfHook, pkg-config, varnish, libmhash, docutils, coreutils, version, sha256 }:
+
+stdenv.mkDerivation rec {
+  pname = "${varnish.name}-digest";
+  inherit version;
+
+  src = fetchFromGitHub {
+    owner = "varnish";
+    repo = "libvmod-digest";
+    rev = version;
+    inherit sha256;
+  };
+
+  nativeBuildInputs = [ autoreconfHook pkg-config docutils ];
+  buildInputs = [ varnish libmhash ];
+
+  postPatch = ''
+    substituteInPlace autogen.sh  --replace "''${dataroot}/aclocal"                  "${varnish.dev}/share/aclocal"
+    substituteInPlace Makefile.am --replace "''${LIBVARNISHAPI_DATAROOTDIR}/aclocal" "${varnish.dev}/share/aclocal"
+  '';
+
+  configureFlags = [ "VMOD_DIR=$(out)/lib/varnish/vmods" ];
+
+  NIX_CFLAGS_COMPILE = [ "-Wno-error=deprecated-declarations" ];
+
+  doCheck = true;
+
+  meta = with lib; {
+    description = "Digest and HMAC vmod";
+    homepage = "https://github.com/varnish/libvmod-digest";
+    inherit (varnish.meta) license platforms maintainers;
+  };
+}