sched/topology: Fix build_sched_groups() comment

The comment was introduced (pre 2.6.12) by:

  8a7a2318 ("[PATCH] sched: consolidate sched domains")

and referred to sched_group->cpu_power. This was folded into
sched_group->sched_group_power in

  commit 9c3f75cb ("sched: Break out cpu_power from the sched_group structure")

The comment was then updated in:

  ced549fa ("sched: Remove remaining dubious usage of "power"")

but should have replaced "sg->cpu_capacity" with
"sg->sched_group_capacity". Do that now.
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Cc: Dietmar.Eggemann@arm.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: morten.rasmussen@arm.com
Cc: qais.yousef@arm.com
Link: http://lkml.kernel.org/r/20190409173546.4747-3-valentin.schneider@arm.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

kernel/sched/topology.c

@@ -1087,8 +1087,8 @@ static struct sched_group *get_group(int cpu, struct sd_data *sdd)
 
 /*
  * build_sched_groups will build a circular linked list of the groups
- * covered by the given span, and will set each group's ->cpumask correctly,
- * and ->cpu_capacity to 0.
+ * covered by the given span, will set each group's ->cpumask correctly,
+ * and will initialize their ->sgc.
  *
  * Assumes the sched_domain tree is fully constructed
  */