Fix plugin success rate logging

Summary:
I noticed that during a refactor, plugin success-rate failures started getting reported as successes.
Thankfully it's only the plugin metrics that are affected.

Reviewed By: passy

Differential Revision: D15394864

fbshipit-source-id: d9f44a0dd61f68dcdcbf2eb524821a3eb023231b

src/utils/metrics.js

@@ -95,7 +95,7 @@ function logPluginSuccessRate(name: string, plugin: string, result: Result) {
     getInstance().track(
       'success-rate',
       name,
-      {value: 1, error: extractMessage(result.error)},
+      {value: 0, error: extractMessage(result.error)},
       plugin,
     );
   }