mm/damon/tests/core-kunit: verify the 'age' field in damon_test_split_at()

mm/damon/tests/core-kunit: verify the 'age' field in damon_test_split_at()

Patch series "mm/damon/tests/core-kunit: extend existing test scenarios",
v2.

Improve the KUnit test coverage for DAMON.

The five patches in this series respectively extend damon_test_split_at(),
damon_test_merge_two(), damon_test_merge_regions_of(),
damon_test_split_regions_of(), and damos_test_commit_quota_goal().

This patch (of 5):

Extend damon_test_split_at() to verify the 'age' field.

Link: https://lkml.kernel.org/r/20251224042200.2061847-1-shu17az@gmail.com
Link: https://lkml.kernel.org/r/20251224042200.2061847-2-shu17az@gmail.com
Signed-off-by: Shu Anzai <shu17az@gmail.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>