CCBC-299 fix constant name in the docs

Change-Id: Ifc32216939eb5c99164c587965d64169eb03f423
Reviewed-on: http://review.couchbase.org/30882
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>