MB-9557: Address segmentation fault on 32-bit arch

- Printing a uint64_t with %d can cause segmentation
fault in 32-bit architectures, %llu would be the correct
usage

Change-Id: I9c713c69a35faab0acd342c1812b4fe860447c5e
Reviewed-on: http://review.couchbase.org/30354
Reviewed-by: Chiyoung Seo <chiyoung@couchbase.com>
Tested-by: Chiyoung Seo <chiyoung@couchbase.com>