sched/fair: Fix issue with trace flag not being set properly

During scheduler boost the sched_task_load ftrace event might not log
the correct flag value. Ensure that the flag is always initialized with
the selected cluster information.

Change-Id: Ia986d0fbc512c8e9ed1b5fb5b2ac4bc564cc4ba9
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>