sched: fair: Fix IRQ awareness

Pass in the right variable (the cpu iterator) to
sched_cpu_high_irqload(), rather than smp_processor_id().

Change-Id: Iaeda55f0fd0ef6e87ebe244aae70a38285df4f2f
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>