Fix compile error on ubuntu

Change-Id: I56177b9b4cb6a60fe38cb3565a45cc7a04ef1ae4
Reviewed-on: http://review.couchbase.org/32320
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>