Add WITH_BENCHMARK (#301)

Author: ThomsonTan

exporters/user_events/CMakeLists.txt

@@ -111,12 +111,14 @@ if(BUILD_TESTING)
     TEST_LIST user_events_logs_exporter_test)
 endif()
 
-find_package(benchmark CONFIG REQUIRED)
-add_executable(user_events_logger_benchmark benchmark/logger_benchmark.cc)
-target_link_libraries(
-  user_events_logger_benchmark benchmark::benchmark ${CMAKE_THREAD_LIBS_INIT}
-  ${CMAKE_THREAD_LIBS_INIT} opentelemetry_logs
-  opentelemetry_exporter_user_events_logs)
+if(WITH_BENCHMARK)
+  find_package(benchmark CONFIG REQUIRED)
+  add_executable(user_events_logger_benchmark benchmark/logger_benchmark.cc)
+  target_link_libraries(
+    user_events_logger_benchmark benchmark::benchmark ${CMAKE_THREAD_LIBS_INIT}
+    ${CMAKE_THREAD_LIBS_INIT} opentelemetry_logs
+    opentelemetry_exporter_user_events_logs)
+endif()
 
 install(
   TARGETS opentelemetry_exporter_user_events_logs