MB-9504: Remove duplicate implementation of ntohll

Change-Id: Id2a27b1a93eadb3130a9038d4508ffaab109ff85
Reviewed-on: http://review.couchbase.org/30293
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Volker Mische <volker.mische@gmail.com>