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/pam/pam-file-contents.nix

@@ -0,0 +1,25 @@
+let
+  name = "pam";
+in
+import ../make-test-python.nix ({ pkgs, ... }: {
+
+  nodes.machine = { ... }: {
+    imports = [ ../../modules/profiles/minimal.nix ];
+
+    krb5.enable = true;
+
+    users = {
+      mutableUsers = false;
+      users = {
+        user = {
+          isNormalUser = true;
+        };
+      };
+    };
+  };
+
+  testScript = builtins.replaceStrings
+    [ "@@pam_ccreds@@" "@@pam_krb5@@" ]
+    [ pkgs.pam_ccreds.outPath pkgs.pam_krb5.outPath ]
+    (builtins.readFile ./test_chfn.py);
+})