sched: Clean up some typos and grammatical errors in code/comments

Signed-off-by: Zhihui Zhang <zzhsuny@gmail.com>
Cc: peterz@infradead.org
Link: http://lkml.kernel.org/r/1411262676-19928-1-git-send-email-zzhsuny@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index aa0f73b..1bc6aad 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -188,7 +188,7 @@
 	raw_spinlock_t lock;
 	ktime_t period;
 	u64 quota, runtime;
-	s64 hierarchal_quota;
+	s64 hierarchical_quota;
 	u64 runtime_expires;
 
 	int idle, timer_active;