Unbreak parallel make.

Change-Id: I433354a57d995620a43a25598978ebbfb97f9bd5
Reviewed-on: http://review.couchbase.org/32387
Tested-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>