Deadlock occurred when entryLogPerLedgerEnabled is true

**BUG REPORT**

Recently I'm doing benchmark on bookie with entryLogPerLedgerEnabled = true, I found the process happened deadlock and hence cann't service normally, here is the threaddump information while error occured.


Bookkeer Versoin: 4.15.0

Here is our customize configuration
`ledgerStorageClass=org.apache.bookkeeper.bookie.SortedLedgerStorage`
`entryLogPerLedgerEnabled=true`
`maximumNumberOfActiveEntryLogs=10000`

It seems caused by acquire lock while EntryMemTableParallelFlusher is running , and the deadlock may happen like this

1. Memtable reach size limit
2. ledger A and ledger B start flush asynchronous, and they both acquire lock successfully
3. when thread enters getCurrentLogWithDirInfoForLedger method, it will calls ledgerIdEntryLogMap#get(ledgerId), if ledgerIdEntryLogMap is out of capacity and trigger cleanup ledger A、B, thus onCacheEntryRemoval is invoked, this method attempt to acquire lock , Note if thread A(thread which run ledger A) exactly execute cleanup ledger B ,and thread B execute cleanup ledger A, deadlock is happened.