Adapt the comments in fdb_compact_upto API
Adapt the comments in fdb_compact_upto API

Change-Id: I38e3c2d702557e03eabd9c71db474f2ca79a7e49

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