fix typos concerning "hierarchy"

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 9a50c5f..1a10978 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -105,7 +105,7 @@
 	/* for custom sched domain */
 	int relax_domain_level;
 
-	/* used for walking a cpuset heirarchy */
+	/* used for walking a cpuset hierarchy */
 	struct list_head stack_list;
 };