perf stat: Allocate evsel->stats->aggr properly

perf stat: Allocate evsel->stats->aggr properly

The perf_stat_config.aggr_map should have a correct size of the
aggregation map.  Use it to allocate aggr_counts.

Also AGGR_NONE with per-core events can be tricky because it doesn't
aggreate basically but it needs to do so for per-core events only.
So only per-core evsels will have stats->aggr data.

Note that other caller of evlist__alloc_stat() might not have
stat_config or aggr_map.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Link: https://lore.kernel.org/r/20221018020227.85905-9-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>