Drop support for logging macro

The way its implemented isn't supported in C89

Change-Id: I224a59c0e9ad6508fd5cb85389ce14f3c3037738
Reviewed-on: http://review.couchbase.org/26923
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>