Drop support for logging macro

The way its implemented isn't supported in C89

Change-Id: I709b85a7d1ab795da9c6a4c6919d2354380b04df
Reviewed-on: http://review.couchbase.org/25982
Tested-by: Trond Norbye <trond.norbye@gmail.com>
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>