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/monitoring/prometheus/varnish-exporter.nix

@@ -0,0 +1,31 @@
+{ lib, buildGoModule, fetchFromGitHub, makeWrapper, varnish, nixosTests }:
+
+buildGoModule rec {
+  pname = "prometheus_varnish_exporter";
+  version = "1.6.1";
+
+  src = fetchFromGitHub {
+    owner = "jonnenauha";
+    repo = "prometheus_varnish_exporter";
+    rev = version;
+    sha256 = "15w2ijz621caink2imlp1666j0ih5pmlj62cbzggyb34ncl37ifn";
+  };
+
+  vendorSha256 = "00i9znb1pk5jpmyhxfg9zbw935fk3c1r0qrgf868xlcf9p8x2rrz";
+
+  nativeBuildInputs = [ makeWrapper ];
+
+  postInstall = ''
+    wrapProgram $out/bin/prometheus_varnish_exporter \
+      --prefix PATH : "${varnish}/bin"
+  '';
+
+  passthru.tests = { inherit (nixosTests.prometheus-exporters) varnish; };
+
+  meta = {
+    homepage = "https://github.com/jonnenauha/prometheus_varnish_exporter";
+    description = "Varnish exporter for Prometheus";
+    license = lib.licenses.mit;
+    maintainers = with lib.maintainers; [ MostAwesomeDude willibutz ];
+  };
+}