sched/fair: Optimize find_busiest_queue()

Use for_each_cpu_and() and thereby avoid computing the capacity for
CPUs we know we're not interested in.

Reviewed-by: Paul Turner <pjt@google.com>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-lppceyv6kb3a19g8spmrn20b@git.kernel.org


Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>

Original commit: https://github.com/googyanas/GoogyMax-S6/commit/53a105dba4656fae8393595d4fe9e5c37c4be2ff