dm stats: fix a leaked s->histogram_boundaries array
am: bad6c16b81

Change-Id: I2e0f245f2f4080cd374009a7f5b834b160cfedc4
diff --git a/drivers/md/dm-stats.c b/drivers/md/dm-stats.c
index 38b05f2..0250e7e 100644
--- a/drivers/md/dm-stats.c
+++ b/drivers/md/dm-stats.c
@@ -175,6 +175,7 @@
 	int cpu;
 	struct dm_stat *s = container_of(head, struct dm_stat, rcu_head);
 
+	kfree(s->histogram_boundaries);
 	kfree(s->program_id);
 	kfree(s->aux_data);
 	for_each_possible_cpu(cpu) {