perf session: Remove superfluous callchain_cursor member

Since we have it in evsel->hists.callchain_cursor, remove it from
perf_session.

One more step in disentangling several places from requiring a
perf_session pointer.

Cc: David Ahern <dsahern@gmail.com>
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-rxr5dj3di7ckyfmnz0naku1z@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 758a287..b7ab373 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -65,7 +65,7 @@
 	struct hist_entry *he;
 
 	if ((sort__has_parent || symbol_conf.use_callchain) && sample->callchain) {
-		err = perf_session__resolve_callchain(session, al->thread,
+		err = perf_session__resolve_callchain(session, evsel, al->thread,
 						      sample->callchain, &parent);
 		if (err)
 			return err;
@@ -76,7 +76,8 @@
 		return -ENOMEM;
 
 	if (symbol_conf.use_callchain) {
-		err = callchain_append(he->callchain, &session->callchain_cursor,
+		err = callchain_append(he->callchain,
+				       &evsel->hists.callchain_cursor,
 				       sample->period);
 		if (err)
 			return err;