perf tools: Future-proof thread_map allocation size calculation

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/20150625174840.GH3253@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Author: acmel

tools/perf/util/thread_map.c

@@ -22,7 +22,7 @@ static int filter(const struct dirent *dir)
 
 static struct thread_map *thread_map__realloc(struct thread_map *map, int nr)
 {
-	size_t size = sizeof(*map) + sizeof(pid_t) * nr;
+	size_t size = sizeof(*map) + sizeof(map->map[0]) * nr;
 
 	return realloc(map, size);
 }