sched/fair: Trivial correction of the newidle_balance() comment

[ Upstream commit 5b78f2dc ]

idle_balance() has been renamed to newidle_balance(). To differentiate
with nohz_idle_balance, it seems refining the comment will be helpful
for the readers of the code.

Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20201202220641.22752-1-song.bao.hua@hisilicon.com


Stable-dep-of: 17e3e88e ("sched/fair: Fix pelt lost idle time detection")
Signed-off-by: Sasha Levin <sashal@kernel.org>