Changes

logging: use ?LOG macro instead of calling logger:level()

The difference between using the macros and the exported functions
is that macros add location (originator) information to the metadata,
and perform lazy evaluation by wrapping the logger call in a case
statement, so it is only evaluated if the log level of the event
passes the primary log level check.

https://www.erlang.org/doc/apps/kernel/logger_chapter.html#logger-api

Change-Id: I3b6e4296f736f9c87d2706ef5fb75146fd9f1239