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/lxd-nftables.nix

@@ -0,0 +1,51 @@
+# This test makes sure that lxd stops implicitly depending on iptables when
+# user enabled nftables.
+#
+# It has been extracted from `lxd.nix` for clarity, and because switching from
+# iptables to nftables requires a full reboot, which is a bit hard inside NixOS
+# tests.
+
+import ./make-test-python.nix ({ pkgs, ...} : {
+  name = "lxd-nftables";
+
+  meta = with pkgs.lib.maintainers; {
+    maintainers = [ patryk27 ];
+  };
+
+  nodes.machine = { lib, ... }: {
+    virtualisation = {
+      lxd.enable = true;
+    };
+
+    networking = {
+      firewall.enable = false;
+      nftables.enable = true;
+      nftables.ruleset = ''
+        table inet filter {
+          chain incoming {
+            type filter hook input priority 0;
+            policy accept;
+          }
+
+          chain forward {
+            type filter hook forward priority 0;
+            policy accept;
+          }
+
+          chain output {
+            type filter hook output priority 0;
+            policy accept;
+          }
+        }
+      '';
+    };
+  };
+
+  testScript = ''
+    machine.wait_for_unit("network.target")
+
+    with subtest("When nftables are enabled, lxd doesn't depend on iptables anymore"):
+        machine.succeed("lsmod | grep nf_tables")
+        machine.fail("lsmod | grep ip_tables")
+  '';
+})