Incorporate PR review feedback

Author: Ramblurr

checks/default.nix

@@ -123,11 +123,13 @@ let
       id = "credentials";
       modules = [ ({ config, pkgs, ... }: {
         # This is the guest vm config
-        microvm.credentialFiles.SECRET_BOOTSTRAP_KEY = "/etc/microvm-bootstrap.secret";
-        microvm.testing.enableTest = builtins.elem config.microvm.hypervisor [
-          # Hypervisors that support systemd credentials
-          "qemu"
-        ];
+        microvm = {
+          credentialFiles.SECRET_BOOTSTRAP_KEY = "/etc/microvm-bootstrap.secret";
+          testing.enableTest = builtins.elem config.microvm.hypervisor [
+            # Hypervisors that support systemd credentials
+            "qemu"
+          ];
+        };
         # TODO: need to somehow have the test harness check for the success or failure of this service.
         systemd.services.test-secret-availability = {
           serviceConfig = {