sched/headers: Fix typo

I cannot spell 'throttling'.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180530224940.17839-1-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>

kernel/sched/sched.h

@@ -983,7 +983,7 @@ static inline void rq_clock_skip_update(struct rq *rq)
 }
 
 /*
- * See rt task throttoling, which is the only time a skip
+ * See rt task throttling, which is the only time a skip
  * request is cancelled.
  */
 static inline void rq_clock_cancel_skipupdate(struct rq *rq)