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/croc.nix

@@ -0,0 +1,51 @@
+import ./make-test-python.nix ({ pkgs, ... }:
+let
+  client = { pkgs, ... }: {
+    environment.systemPackages = [ pkgs.croc ];
+  };
+  pass = pkgs.writeText "pass" "PassRelay";
+in {
+  name = "croc";
+  meta = with pkgs.lib.maintainers; {
+    maintainers = [ hax404 julm ];
+  };
+
+  nodes = {
+    relay = {
+      services.croc = {
+        enable = true;
+        pass = pass;
+        openFirewall = true;
+      };
+    };
+    sender = client;
+    receiver = client;
+  };
+
+  testScript = ''
+    start_all()
+
+    # wait until relay is up
+    relay.wait_for_unit("croc")
+    relay.wait_for_open_port(9009)
+    relay.wait_for_open_port(9010)
+    relay.wait_for_open_port(9011)
+    relay.wait_for_open_port(9012)
+    relay.wait_for_open_port(9013)
+
+    # generate testfiles and send them
+    sender.wait_for_unit("multi-user.target")
+    sender.execute("echo Hello World > testfile01.txt")
+    sender.execute("echo Hello Earth > testfile02.txt")
+    sender.execute(
+        "croc --pass ${pass} --relay relay send --code topSecret testfile01.txt testfile02.txt >&2 &"
+    )
+
+    # receive the testfiles and check them
+    receiver.succeed(
+        "croc --pass ${pass} --yes --relay relay topSecret"
+    )
+    assert "Hello World" in receiver.succeed("cat testfile01.txt")
+    assert "Hello Earth" in receiver.succeed("cat testfile02.txt")
+  '';
+})