cbtransfer shows incorrect count(after expiring some items) while transferring items from one bucket to another

When some items are expired in a bucket and then cbtransfer is used to transfer messages to another bucket, then total item count shown is wrong.

To Reproduce:

1. Take a node. Create Bucket. Load 100K items in it.
2. Expire some items (in my case I expired 60%).
3. Wait till items are expired (or run expiry pager). You will see that 40K items remains (I can see 40001 items on UI, so its correct).
4. Execute the command :

./cbtransfer http://Administrator:password@10.3.3.59 http://Administrator:password@10.3.3.59:8091 -b default -B new_bucket -v -v

5. UI shows that there are 40001 items in the new bucket (thats expected too).

But in the output of cbtransfer, you will find (not pasting the complete output) :

############################################################################### 400.0% (159999/40001 msgs)

So we see that around 160K items have been transferred, infact only 100K items were loaded initially and out of that 60K are already expired.

Collectinfo at : http://s3.amazonaws.com/bugdb/jira/MB-9075/e9125b6b/collectinfo_cbtransfer.zip