m/n/c/roleserve/controlplane: wrap tpm errors

Change-Id: I0ec10b6065c529b7772a884fd48c7c6f7b5df0bc
Reviewed-on: https://review.monogon.dev/c/monogon/+/1383
Reviewed-by: Leopold Schabel <leo@monogon.tech>
Tested-by: Jenkins CI
diff --git a/metropolis/node/core/roleserve/worker_controlplane.go b/metropolis/node/core/roleserve/worker_controlplane.go
index e5c6efb..885b39e 100644
--- a/metropolis/node/core/roleserve/worker_controlplane.go
+++ b/metropolis/node/core/roleserve/worker_controlplane.go
@@ -361,7 +361,7 @@
 					return fmt.Errorf("couldn't marshal ClusterDirectory: %w", err)
 				}
 				if err = s.storageRoot.ESP.Metropolis.ClusterDirectory.Write(cdirRaw, 0644); err != nil {
-					return err
+					return fmt.Errorf("writing cluster directory failed: %w", err)
 				}
 
 				sc := ppb.SealedConfiguration{
@@ -370,7 +370,7 @@
 					ClusterCa:     caCert,
 				}
 				if err = s.storageRoot.ESP.Metropolis.SealedConfiguration.SealSecureBoot(&sc); err != nil {
-					return err
+					return fmt.Errorf("writing sealed configuration failed: %w", err)
 				}
 
 				supervisor.Logger(ctx).Infof("Saved bootstrapped node's credentials.")