MB-11274 Fix modifying the freed memory
MB-11274 Fix modifying the freed memory

- 'compaction_flag' in 'struct openfiles_elem' is modified after the
corresponding file is detached from the compactor, and the memory
area is freed.

wurikiji/forestdb,uvenum/forestdb,sushmaad/forestdb,joliss/forestdb,seem-sky/forestdb,yyangpan/forestdb,jinxuan/forestdb,wurikiji/forestdb,joliss/forestdb,couchbase/forestdb,yyangpan/forestdb,nvoron23/forestdb,uvenum/forestdb,zhaog/forestdb,couchbase/forestdb,hisundar/forestdb,nvoron23/forestdb,seem-sky/forestdb,sushmaad/forestdb,hisundar/forestdb,zhaog/forestdb,jinxuan/forestdb