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>

nixos/modules/services/mail/mailhog.nix

@@ -0,0 +1,82 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.services.mailhog;
+
+  args = lib.concatStringsSep " " (
+    [
+      "-api-bind-addr :${toString cfg.apiPort}"
+      "-smtp-bind-addr :${toString cfg.smtpPort}"
+      "-ui-bind-addr :${toString cfg.uiPort}"
+      "-storage ${cfg.storage}"
+    ] ++ lib.optional (cfg.storage == "maildir")
+      "-maildir-path $STATE_DIRECTORY"
+    ++ cfg.extraArgs
+  );
+
+in
+{
+  ###### interface
+
+  imports = [
+    (mkRemovedOptionModule [ "services" "mailhog" "user" ] "")
+  ];
+
+  options = {
+
+    services.mailhog = {
+      enable = mkEnableOption "MailHog";
+
+      storage = mkOption {
+        type = types.enum [ "maildir" "memory" ];
+        default = "memory";
+        description = "Store mails on disk or in memory.";
+      };
+
+      apiPort = mkOption {
+        type = types.port;
+        default = 8025;
+        description = "Port on which the API endpoint will listen.";
+      };
+
+      smtpPort = mkOption {
+        type = types.port;
+        default = 1025;
+        description = "Port on which the SMTP endpoint will listen.";
+      };
+
+      uiPort = mkOption {
+        type = types.port;
+        default = 8025;
+        description = "Port on which the HTTP UI will listen.";
+      };
+
+      extraArgs = mkOption {
+        type = types.listOf types.str;
+        default = [];
+        description = "List of additional arguments to pass to the MailHog process.";
+      };
+    };
+  };
+
+
+  ###### implementation
+
+  config = mkIf cfg.enable {
+
+    systemd.services.mailhog = {
+      description = "MailHog - Web and API based SMTP testing";
+      after = [ "network.target" ];
+      wantedBy = [ "multi-user.target" ];
+      serviceConfig = {
+        Type = "exec";
+        ExecStart = "${pkgs.mailhog}/bin/MailHog ${args}";
+        DynamicUser = true;
+        Restart = "on-failure";
+        StateDirectory = "mailhog";
+      };
+    };
+  };
+}