luci_config: Fail if a step fails

Change-Id: Ibd5af323abcda95d76cfa28f0953b7dae89fc5ce
Reviewed-on: https://pigweed-review.googlesource.com/c/infra/recipes/+/98060
Pigweed-Auto-Submit: Rob Mohr <mohrr@google.com>
Reviewed-by: Ted Pudlik <tpudlik@google.com>
Commit-Queue: Auto-Submit <auto-submit@pigweed.google.com.iam.gserviceaccount.com>
diff --git a/recipes/luci_config.py b/recipes/luci_config.py
index 9102939..f6a8cc7 100644
--- a/recipes/luci_config.py
+++ b/recipes/luci_config.py
@@ -63,7 +63,9 @@
                 ]
                 futures.append(api.futures.spawn(api.step, relative_path, cmd))
 
-    api.futures.wait(futures)
+        api.futures.wait(futures)
+        for f in futures:
+            f.result()
 
 
 def GenTests(api):