Filemgr_openlock to be acquired for a hash table scan
Filemgr_openlock to be acquired for a hash table scan

Context: filemgr_shutdown() in src/filemgr.cc

Change-Id: I413eb81c134c59a4589d9d7c08f590c15a0506de
Reviewed-on: http://review.couchbase.org/62461
Tested-by: buildbot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Chiyoung Seo <fcffc23db27b19ee4ebba46695ee6b50e09216a2@couchbase.com>

couchbase/forestdb,couchbase/forestdb,wurikiji/forestdb,wurikiji/forestdb,hisundar/forestdb,hisundar/forestdb