m/cli/metroctl: fix confusing logs

If there is an error, it previously logged both the error and success
message, which is confusing.

Change-Id: I2b4cbed205a035eae2b10412a527536593f38e24
Reviewed-on: https://review.monogon.dev/c/monogon/+/3384
Reviewed-by: Serge Bazanski <serge@monogon.tech>
Tested-by: Jenkins CI
diff --git a/metropolis/cli/metroctl/cmd_node_set.go b/metropolis/cli/metroctl/cmd_node_set.go
index 949f262..73d7f3c 100644
--- a/metropolis/cli/metroctl/cmd_node_set.go
+++ b/metropolis/cli/metroctl/cmd_node_set.go
@@ -79,8 +79,9 @@
 		_, err := mgmt.UpdateNodeRoles(ctx, req)
 		if err != nil {
 			log.Printf("Couldn't update node \"%s\": %v", node, err)
+		} else {
+			log.Printf("Updated node %s.", node)
 		}
-		log.Printf("Updated node %s.", node)
 	}
 }
 
@@ -118,7 +119,8 @@
 		_, err := mgmt.UpdateNodeRoles(ctx, req)
 		if err != nil {
 			log.Printf("Couldn't update node \"%s\": %v", node, err)
+		} else {
+			log.Printf("Updated node %s.", node)
 		}
-		log.Printf("Updated node %s.", node)
 	}
 }