c++|ez|fbBenchmark| migrate pollIOBackend options to IoUringOptions

Summary: killing the remaining stragglers of this PollIoBackend

Reviewed By: spikeh, dtolnay

Differential Revision: D92847480

fbshipit-source-id: 81b11086de6917d29a04265019872a128643c473

Author: jlhe97

third-party/folly/src/folly/io/async/test/RegisteredFdBenchmark.cpp

@@ -95,7 +95,7 @@ class BackendEventBase : public EventBase {
  private:
   static std::unique_ptr<folly::EventBaseBackendBase> getBackend(
       bool useRegisteredFds, size_t capacity) {
-    folly::PollIoBackend::Options options;
+    folly::IoUringOptions options;
     options.setCapacity(capacity)
         .setMaxSubmit(256)
         .setMaxGet(128)