Fix warning messages due to ignoring return value of 'system' call
Fix warning messages due to ignoring return value of 'system' call

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