sched/nohz: Fix logic in trigger_load_balance
Whether we need to kick nohz does not depend on current rq->next_balance,
meaning it does not depend on the check of previous if condition.

Change-Id: I566011d6341fa7a9a700c834f77e129043eaba11
Signed-off-by: Xin Qi <xqi@codeaurora.org>