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/tests/postfix.nix

@@ -0,0 +1,77 @@
+let
+  certs = import ./common/acme/server/snakeoil-certs.nix;
+  domain = certs.domain;
+in
+import ./make-test-python.nix {
+  name = "postfix";
+
+  nodes.machine = { pkgs, ... }: {
+    imports = [ common/user-account.nix ];
+    services.postfix = {
+      enable = true;
+      enableSubmission = true;
+      enableSubmissions = true;
+      tlsTrustedAuthorities = "${certs.ca.cert}";
+      sslCert = "${certs.${domain}.cert}";
+      sslKey = "${certs.${domain}.key}";
+      submissionsOptions = {
+          smtpd_sasl_auth_enable = "yes";
+          smtpd_client_restrictions = "permit";
+          milter_macro_daemon_name = "ORIGINATING";
+      };
+    };
+
+    security.pki.certificateFiles = [
+      certs.ca.cert
+    ];
+
+    networking.extraHosts = ''
+      127.0.0.1 ${domain}
+    '';
+
+    environment.systemPackages = let
+      sendTestMail = pkgs.writeScriptBin "send-testmail" ''
+        #!${pkgs.python3.interpreter}
+        import smtplib
+
+        with smtplib.SMTP('${domain}') as smtp:
+          smtp.sendmail('root@localhost', 'alice@localhost', 'Subject: Test\n\nTest data.')
+          smtp.quit()
+      '';
+
+      sendTestMailStarttls = pkgs.writeScriptBin "send-testmail-starttls" ''
+        #!${pkgs.python3.interpreter}
+        import smtplib
+        import ssl
+
+        ctx = ssl.create_default_context()
+
+        with smtplib.SMTP('${domain}') as smtp:
+          smtp.ehlo()
+          smtp.starttls(context=ctx)
+          smtp.ehlo()
+          smtp.sendmail('root@localhost', 'alice@localhost', 'Subject: Test STARTTLS\n\nTest data.')
+          smtp.quit()
+      '';
+
+      sendTestMailSmtps = pkgs.writeScriptBin "send-testmail-smtps" ''
+        #!${pkgs.python3.interpreter}
+        import smtplib
+        import ssl
+
+        ctx = ssl.create_default_context()
+
+        with smtplib.SMTP_SSL(host='${domain}', context=ctx) as smtp:
+          smtp.sendmail('root@localhost', 'alice@localhost', 'Subject: Test SMTPS\n\nTest data.')
+          smtp.quit()
+      '';
+    in [ sendTestMail sendTestMailStarttls sendTestMailSmtps ];
+  };
+
+  testScript = ''
+    machine.wait_for_unit("postfix.service")
+    machine.succeed("send-testmail")
+    machine.succeed("send-testmail-starttls")
+    machine.succeed("send-testmail-smtps")
+  '';
+}