diff --git a/tools/perf/ui/stdio/hist.c b/tools/perf/ui/stdio/hist.c
index 6c15268..c244cb5 100644
--- a/tools/perf/ui/stdio/hist.c
+++ b/tools/perf/ui/stdio/hist.c
@@ -213,20 +213,19 @@
 	return ret;
 }
 
-static size_t __callchain__fprintf_flat(FILE *fp,
-					struct callchain_node *self,
+static size_t __callchain__fprintf_flat(FILE *fp, struct callchain_node *node,
 					u64 total_samples)
 {
 	struct callchain_list *chain;
 	size_t ret = 0;
 
-	if (!self)
+	if (!node)
 		return 0;
 
-	ret += __callchain__fprintf_flat(fp, self->parent, total_samples);
+	ret += __callchain__fprintf_flat(fp, node->parent, total_samples);
 
 
-	list_for_each_entry(chain, &self->val, list) {
+	list_for_each_entry(chain, &node->val, list) {
 		if (chain->ip >= PERF_CONTEXT_MAX)
 			continue;
 		if (chain->ms.sym)
@@ -239,15 +238,14 @@
 	return ret;
 }
 
-static size_t callchain__fprintf_flat(FILE *fp, struct rb_root *self,
+static size_t callchain__fprintf_flat(FILE *fp, struct rb_root *tree,
 				      u64 total_samples)
 {
 	size_t ret = 0;
 	u32 entries_printed = 0;
-	struct rb_node *rb_node;
 	struct callchain_node *chain;
+	struct rb_node *rb_node = rb_first(tree);
 
-	rb_node = rb_first(self);
 	while (rb_node) {
 		double percent;