sched: EAS: Fix the condition to distinguish energy before/after

Before commit 5f8b3a7 ("sched/fair: consider task utilization in
group_norm_util()"), eenv->util_delta is used to distinguish energy
before and energy after in sched_group_energy(). After that commit,
eenv->util_delta can not do that any more.

In this commit, use trg_cpu to distinguish energy before/after in
sched_group_energy().

Before apply this commit, cap_before/cap_delta is not correct:
<idle>-0 [001] 147504.608920: sched_energy_diff: pid=7 comm=rcu_preempt
src_cpu=1 dst_cpu=3 usage_delta=7 nrg_before=250 nrg_after=250 nrg_diff=0
cap_before=0 cap_after=528 cap_delta=1056 nrg_delta=0 nrg_payoff=0

After apply this commit, cap_before/cap_delta retrun to normal:
<idle>-0 [001] 220.494011: sched_energy_diff:    pid=7 comm=rcu_preempt
src_cpu=1 dst_cpu=2 usage_delta=3 nrg_before=248 nrg_after=248 nrg_diff=0
cap_before=528 cap_after=528 cap_delta=0 nrg_delta=0 nrg_payoff=0

Signed-off-by: Ke Wang <ke.wang@spreadtrum.com>

Author: Ke Wang

kernel/sched/fair.c

@@ -5534,13 +5534,13 @@ static int sched_group_energy(struct energy_env *eenv)
 
 				if (sg->group_weight == 1) {
 					/* Remove capacity of src CPU (before task move) */
-					if (eenv->util_delta == 0 &&
+					if (eenv->trg_cpu == eenv->src_cpu &&
 					    cpumask_test_cpu(eenv->src_cpu, sched_group_cpus(sg))) {
 						eenv->cap.before = sg->sge->cap_states[cap_idx].cap;
 						eenv->cap.delta -= eenv->cap.before;
 					}
 					/* Add capacity of dst CPU  (after task move) */
-					if (eenv->util_delta != 0 &&
+					if (eenv->trg_cpu == eenv->dst_cpu &&
 					    cpumask_test_cpu(eenv->dst_cpu, sched_group_cpus(sg))) {
 						eenv->cap.after = sg->sge->cap_states[cap_idx].cap;
 						eenv->cap.delta += eenv->cap.after;