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/applications/networking/mullvad/libwg.nix

@@ -0,0 +1,35 @@
+{ lib
+, buildGoModule
+, fetchFromGitHub
+, mullvad
+}:
+buildGoModule {
+  pname = "libwg";
+
+  inherit (mullvad)
+    version
+    src
+    ;
+
+  sourceRoot = "source/wireguard/libwg";
+
+  vendorSha256 = "qvymWCdJ+GY90W/Fpdp+r1+mTq6O4LyN2Yw/PjKdFm0=";
+
+  # XXX: hack to make the ar archive go to the correct place
+  # This is necessary because passing `-o ...` to `ldflags` does not work
+  # (this doesn't get communicated everywhere in the chain, apparently, so
+  # `go` complains that it can't find an `a.out` file).
+  GOBIN = "${placeholder "out"}/lib";
+  ldflags = [ "-s" "-w" "-buildmode=c-archive" ];
+
+  postInstall = ''
+    mv $out/lib/libwg{,.a}
+  '';
+
+  meta = with lib; {
+    description = "A tiny wrapper around wireguard-go";
+    homepage = "https://github.com/mullvad/mullvadvpn-app/tree/master/wireguard/libwg";
+    license = licenses.gpl3Only;
+    maintainers = with maintainers; [ cole-h ];
+  };
+}