perf tools: Fix thread map that is type pid_t

Thread map is actually type pid_t and not int.
Signed-off-by: Robert Richter <robert.richter@amd.com>
Cc: Ingo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/r/1333643188-26895-3-git-send-email-robert.richter@amd.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/thread_map.h

@@ -6,7 +6,7 @@
 
 struct thread_map {
 	int nr;
-	int map[];
+	pid_t map[];
 };
 
 struct thread_map *thread_map__new_by_pid(pid_t pid);