mm/damon/core-test: add a test for damon_update_monitoring_results()

Add a simple unit test for damon_update_monitoring_results() function.

Link: https://lkml.kernel.org/r/20230119013831.1911-4-sj@kernel.org


Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>