Coverity analysis defect 46425: Unchecked return value in library

A new defect has been detected and assigned to benety.goh in Coverity Connect.
http://coverity.mongodb.com//sourcebrowser.htm?projectId=10001#mergedDefectId=46425
The defect was flagged by checker CHECKED_RETURN in
file /src/mongo/db/storage/storage_engine_metadata.cpp
function mongo::StorageEngineMetadata::write() const
and this ticket was created by milkie