cpufreq: schedutil: fix check for stale utilization values

Part of the fix from commit d86ab9cff8 ("cpufreq: schedutil: use now
as reference when aggregating shared policy requests") is reversed in
commit 05d2ca2420 ("cpufreq: schedutil: Ignore CPU load older than
WALT window size") due to a porting mistake. Restore it while keeping
the relevant change from the latter patch.

Bug: 117438867
Test: build & boot
Change-Id: I21399be760d7c8e2fff6c158368a285dc6261647
Signed-off-by: Connor O'Brien <connoro@google.com>
Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

kernel/sched/cpufreq_schedutil.c

@@ -356,7 +356,6 @@ static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu, u64 time)
 {
 	struct sugov_policy *sg_policy = sg_cpu->sg_policy;
 	struct cpufreq_policy *policy = sg_policy->policy;
-	u64 last_freq_update_time = sg_policy->last_freq_update_time;
 	unsigned long util = 0, max = 1;
 	unsigned int j;
 
@@ -372,7 +371,7 @@ static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu, u64 time)
 		 * enough, don't take the CPU into account as it probably is
 		 * idle now (and clear iowait_boost for it).
 		 */
-		delta_ns = last_freq_update_time - j_sg_cpu->last_update;
+		delta_ns = time - j_sg_cpu->last_update;
 		if (delta_ns > stale_ns) {
 			j_sg_cpu->iowait_boost = 0;
 			j_sg_cpu->iowait_boost_pending = false;