test: allowing >= the real refcount to avoid false alarm

test: allowing >= the real refcount to avoid false alarm

Current dedup allow to contain multiple same sources using
multiset, which results in inconsistent situation as follow
(during set_chunk, but not confined in set_chunk).

1. User issues set_chunk
2. OSD receives the set_chunk, and sends increment message
to an object in the low tier (INPROGRESS).
3. OSD map is changed (841 → 843)
3.5. on_change() is called
4. the set_chunk op is reenqueued by requeue_op()
5. OSD handles the duplicated set_chunk, but it is not able to
 know the set_chunk is duplicated because it does not log on the disk yet.
6. OSD issues increment message again to the object
in the low tier. (increment operation is executed twice)

To fix this, this commit allows >= the real refcount in test cases

fixes: https://tracker.ceph.com/issues/51000

Signed-off-by: Myoungwon Oh <myoungwon.oh@samsung.com>