perf callchain: Rename cumul_hits into callchain_cumul_hits

That makes the callchain API naming more consistent and
reduce potential naming clashes.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1294977121-5700-3-git-send-email-fweisbec@gmail.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index a438a06..02ed318 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -430,7 +430,7 @@
 		u64 cumul;
 
 		child = rb_entry(node, struct callchain_node, rb_node);
-		cumul = cumul_hits(child);
+		cumul = callchain_cumul_hits(child);
 		remaining -= cumul;
 
 		/*