sched: Move call to trace_sched_cpu_load()

select_best_cpu() invokes trace_sched_cpu_load() for all online cpus
in a loop, before it enters the loop for core selection. Moving
invocation of trace_sched_cpu_load() in inner core loop is potentially
more efficient.

Change-Id: Iae1c58b26632edf9ec5f5da905c31356eb95c925
Signed-off-by: Srivatsa Vaddagiri <vatsa@codeaurora.org>
Signed-off-by: Syed Rameez Mustafa <rameezmustafa@codeaurora.org>