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-top.c b/tools/perf/builtin-top.c
index 04288ee..9b3bbb4 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -777,7 +777,7 @@
 
 		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;
@@ -790,7 +790,7 @@
 		}
 
 		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;