MB-100: Logic fix in cbR

Change-Id: Iade4e4d8d46f67d7c74cf467f94289a62610e52c
Reviewed-on: http://review.couchbase.org/27197
Reviewed-by: abhinav dangeti <abhinav.dangeti@gmail.com>
Tested-by: abhinav dangeti <abhinav.dangeti@gmail.com>