perf stat: Fix metric-only aggregation index

Aggregation index was being computed using the evsel's cpumap which
may have a different (typically the same or fewer) entries.

Before:
```
$ perf stat --metric-only -A -M memory_bandwidth_total -a sleep 1

Performance counter stats for 'system wide':

MB/s memory_bandwidth_total MB/s memory_bandwidth_total MB/s memory_bandwidth_total MB/s memory_bandwidth_total MB/s memory_bandwidth_total MB/s memory_bandwidth_total
CPU0 12.8 0.0 12.9 12.7 0.0 12.6
CPU1

1.007806367 seconds time elapsed
```

After:
```
$ perf stat --metric-only -A -M memory_bandwidth_total -a sleep 1

Performance counter stats for 'system wide':

MB/s memory_bandwidth_total MB/s memory_bandwidth_total MB/s memory_bandwidth_total MB/s memory_bandwidth_total MB/s memory_bandwidth_total MB/s memory_bandwidth_total
CPU0 15.4 0.0 15.3 15.0 0.0 14.9
CPU18 0.0 0.0 13.5 5.2 0.0 11.9

1.007858736 seconds time elapsed
```

Signed-off-by: Ian Rogers <[e-mail]> |
Acked-by: Namhyung Kim <[e-mail]>
Cc: K Prateek Nayak <[e-mail]>
Cc: Stephane Eranian <[e-mail]>
Cc: Kaige Ye <[e-mail]>
Cc: Kajol Jain <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Kan Liang <[e-mail]>
Cc: John Garry <[e-mail]>
Signed-off-by: Namhyung Kim <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

tools/perf/util/stat-display.c

···
 			u64 ena, run, val;
 			double uval;
 			struct perf_stat_evsel *ps = counter->stats;
-			int aggr_idx = perf_cpu_map__idx(evsel__cpus(counter), cpu);
+			int aggr_idx = 0;
 
-			if (aggr_idx < 0)
+			if (!perf_cpu_map__has(evsel__cpus(counter), cpu))
 				continue;
+
+			cpu_aggr_map__for_each_idx(aggr_idx, config->aggr_map) {
+				if (config->aggr_map->map[aggr_idx].cpu.cpu == cpu.cpu)
+					break;
+			}
 
 			os->evsel = counter;
 			os->id = aggr_cpu_id__cpu(cpu, /*data=*/NULL);