annotate OIC_LOG_BUFFER when looking for client callback and observer

annotate OIC_LOG_BUFFER when looking for client callback and observer

Printing all token info while looking for client callback or observer
is burden and makes it hard to see entire log message
even though it is needless.

Change-Id: I25e0c3f1922f207a9d6652017495270db34e6bbc
Signed-off-by: Jaewook Jung <jw0213.jung@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/12375
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Ashok Babu Channa <ashok.channa@samsung.com>
(cherry picked from commit ce6822710a2ee2272b2740e6747f219c8c51dfca)
Reviewed-on: https://gerrit.iotivity.org/gerrit/13209
Reviewed-by: Jaehong Jo <jaehong.jo@samsung.com>