perf evlist: Don't die if sample_{id_all|type} is invalid

Fixes two more cases where the python binding would not load:

. Not finding die(), which it shouldn't anyway, not good to just stop the
  world because some particular perf.data file is invalid, just propagate
  the error to the caller.

. Not finding perf_sample_size: fix it by moving it from event.c to evsel,
  where it belongs, as most cases are moving to operate on an evsel object.o

One of the fixed problems:

[root@emilia ~]# python
>>> import perf
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: /home/acme/git/build/perf/python/perf.so: undefined symbol: perf_sample_size
>>>
[root@emilia ~]#

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
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-1hkj7b2cvgbfnoizsekjb6c9@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 04c8a60..b021ea9 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -455,33 +455,46 @@
 	return 0;
 }
 
-u64 perf_evlist__sample_type(struct perf_evlist *evlist)
+bool perf_evlist__valid_sample_type(const struct perf_evlist *evlist)
 {
-	struct perf_evsel *pos;
-	u64 type = 0;
+	struct perf_evsel *pos, *first;
 
-	list_for_each_entry(pos, &evlist->entries, node) {
-		if (!type)
-			type = pos->attr.sample_type;
-		else if (type != pos->attr.sample_type)
-			die("non matching sample_type");
+	pos = first = list_entry(evlist->entries.next, struct perf_evsel, node);
+
+	list_for_each_entry_continue(pos, &evlist->entries, node) {
+		if (first->attr.sample_type != pos->attr.sample_type)
+			return false;
 	}
 
-	return type;
+	return true;
+}
+
+u64 perf_evlist__sample_type(const struct perf_evlist *evlist)
+{
+	struct perf_evsel *first;
+
+	first = list_entry(evlist->entries.next, struct perf_evsel, node);
+	return first->attr.sample_type;
+}
+
+bool perf_evlist__valid_sample_id_all(const struct perf_evlist *evlist)
+{
+	struct perf_evsel *pos, *first;
+
+	pos = first = list_entry(evlist->entries.next, struct perf_evsel, node);
+
+	list_for_each_entry_continue(pos, &evlist->entries, node) {
+		if (first->attr.sample_id_all != pos->attr.sample_id_all)
+			return false;
+	}
+
+	return true;
 }
 
 bool perf_evlist__sample_id_all(const struct perf_evlist *evlist)
 {
-	bool value = false, first = true;
-	struct perf_evsel *pos;
+	struct perf_evsel *first;
 
-	list_for_each_entry(pos, &evlist->entries, node) {
-		if (first) {
-			value = pos->attr.sample_id_all;
-			first = false;
-		} else if (value != pos->attr.sample_id_all)
-			die("non matching sample_id_all");
-	}
-
-	return value;
+	first = list_entry(evlist->entries.next, struct perf_evsel, node);
+	return first->attr.sample_id_all;
 }