perf tools: Get current comm instead of last one

At insert time, a hist entry should reference comm at the time otherwise
it'll get the last comm anyway.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Tested-by: Jiri Olsa <jolsa@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/n/tip-n6pykiiymtgmcjs834go2t8x@git.kernel.org
[ Fixed up const pointer issues ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h
index 8702c6b..373c055 100644
--- a/tools/perf/util/thread.h
+++ b/tools/perf/util/thread.h
@@ -26,6 +26,7 @@
 };
 
 struct machine;
+struct comm;
 
 struct thread *thread__new(pid_t pid, pid_t tid);
 void thread__delete(struct thread *self);
@@ -36,6 +37,7 @@
 
 int thread__set_comm(struct thread *thread, const char *comm, u64 timestamp);
 int thread__comm_len(struct thread *self);
+struct comm *thread__comm(const struct thread *thread);
 const char *thread__comm_str(const struct thread *thread);
 void thread__insert_map(struct thread *self, struct map *map);
 int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp);