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/development/python-modules/attrs/tests.nix

@@ -0,0 +1,21 @@
+{ buildPythonPackage
+, pytestCheckHook
+, attrs
+, hypothesis
+}:
+
+buildPythonPackage {
+  pname = "attrs-tests";
+  inherit (attrs) version;
+
+  srcs = attrs.testout;
+
+  dontBuild = true;
+  dontInstall = true;
+
+  checkInputs = [
+    attrs
+    hypothesis
+    pytestCheckHook
+  ];
+}