2. For the removing the stale macros, the change log can simply state that
the macros are unused in the code and are being removed.

I've split this part into a separate patch, and here is the changelog:

    perf sched: cleanup to remove unused macros

    The macros copied from kernel headers are unused and
    stale in the code and are being removed to avoid confusions.

    Signed-off-by: Ze Gao [off-list ref]

Regards,
Ze