[chore] fix mention of deprecated function in ecsobserver (#31795)

small readme fix to point to ReportStatus.

extension/observer/ecsobserver/README.md

@@ -443,7 +443,7 @@ otel's own /metrics.
 
 ### Error Handling
 
-- Auth and cluster not found error will cause the extension to stop (calling `host.ReportFatalError`). Although IAM role
+- Auth and cluster not found error will cause the extension to stop (calling `ReportStatus`). Although IAM role
   can be updated at runtime without restarting the collector, it's better to fail to make the problem obvious. Same
   applies to cluster not found. In the future we can add config to downgrade those errors if user want to monitor an ECS
   cluster with collector running outside the cluster, the collector can run anywhere as long as it can reach scrape