perf stat: Replace MAX_NR_CPUS with cpu__max_cpu()

The function cpu__max_cpu() returns the possible number of CPUs as
defined in the sysfs and can be used as an alternative for MAX_NR_CPUS
in zero_per_pkg() and check_per_pkg().
Signed-off-by: Kyle Meyer <kyle.meyer@hpe.com>
Reviewed-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <russ.anderson@hpe.com>
Link: http://lore.kernel.org/lkml/20190827214352.94272-4-meyerk@stormcage.eag.rdlabs.hpecorp.netSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/stat.c

@@ -210,7 +210,7 @@ void perf_evlist__reset_stats(struct evlist *evlist)
 static void zero_per_pkg(struct evsel *counter)
 {
 	if (counter->per_pkg_mask)
-		memset(counter->per_pkg_mask, 0, MAX_NR_CPUS);
+		memset(counter->per_pkg_mask, 0, cpu__max_cpu());
 }
 
 static int check_per_pkg(struct evsel *counter,
@@ -229,7 +229,7 @@ static int check_per_pkg(struct evsel *counter,
 		return 0;
 
 	if (!mask) {
-		mask = zalloc(MAX_NR_CPUS);
+		mask = zalloc(cpu__max_cpu());
 		if (!mask)
 			return -ENOMEM;