Fix a signedness warning on Darwin
Fix a signedness warning on Darwin

adfin/mordor,mtanski/mordor,mozy/mordor,adfin/mordor,ccutrer/mordor,cgaebel/mordor,ccutrer/mordor,cgaebel/mordor,adfin/mordor,mtanski/mordor,mozy/mordor,ccutrer/mordor,mtanski/mordor,mozy/mordor