perf session: Use perf_evlist__id_hdr_size more extensively

Removing perf_session->id_hdr_size, as it can be obtained from the
evsel/evlist.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-1nwc2kslu7gsfblu98xbqbll@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
index a2c3ce9..e2a1a4b 100644
--- a/tools/perf/util/session.h
+++ b/tools/perf/util/session.h
@@ -44,7 +44,6 @@
 	int			fd;
 	bool			fd_pipe;
 	bool			repipe;
-	u16			id_hdr_size;
 	int			cwdlen;
 	char			*cwd;
 	struct ordered_samples	ordered_samples;
@@ -83,7 +82,7 @@
 
 int perf_session__create_kernel_maps(struct perf_session *self);
 
-void perf_session__update_sample_type(struct perf_session *self);
+void perf_session__set_id_hdr_size(struct perf_session *session);
 void perf_session__remove_thread(struct perf_session *self, struct thread *th);
 
 static inline