Fix out of source build

Change-Id: I2f0a3e002c6dc61decd08074917284342930a5a7
Reviewed-on: http://review.couchbase.org/35183
Tested-by: Trond Norbye <trond.norbye@gmail.com>
Reviewed-by: Chris Hillery <ceej@couchbase.com>
Tested-by: Chris Hillery <ceej@couchbase.com>