checkin part 2 solution

Signed-off-by: Alex Chi <iskyzh@gmail.com>

mini-lsm/src/tests/harness.rs

@@ -124,10 +124,9 @@ pub fn generate_sst(
     builder.build(id, block_cache, path.as_ref()).unwrap()
 }
 
-
 pub fn sync(storage: &LsmStorageInner) {
     storage
         .force_freeze_memtable(&storage.state_lock.lock())
         .unwrap();
     storage.force_flush_next_imm_memtable().unwrap();
-}
+}