Removed unused field

system/core/fs_mgr/libsnapshot/snapuserd/user-space-merge/handler_manager.h:149:10: error: private field 'perform_verification_' is not used [-Werror,-Wunused-private-field]
  149 |     bool perform_verification_ = true;
      |          ^
1 error generated.

Test: presubmit
Change-Id: I862db34623e3489c05aa614e8a2895bcead785cb
diff --git a/fs_mgr/libsnapshot/snapuserd/user-space-merge/handler_manager.h b/fs_mgr/libsnapshot/snapuserd/user-space-merge/handler_manager.h
index a126387..4ae1e7c 100644
--- a/fs_mgr/libsnapshot/snapuserd/user-space-merge/handler_manager.h
+++ b/fs_mgr/libsnapshot/snapuserd/user-space-merge/handler_manager.h
@@ -146,7 +146,6 @@
     int num_partitions_merge_complete_ = 0;
     std::queue<std::shared_ptr<HandlerThread>> merge_handlers_;
     android::base::unique_fd monitor_merge_event_fd_;
-    bool perform_verification_ = true;
 };
 
 }  // namespace snapshot