sched: Fix kernel-doc markup

Kernel-doc requires that a kernel-doc markup to be immediately
below the function prototype, as otherwise it will rename it.
So, move sys_sched_yield() markup to the right place.

Also fix the cpu_util() markup: Kernel-doc markups
should use this format:
identifier - description

Signed-off-by: Mauro Carvalho Chehab <[e-mail]>
Signed-off-by: Peter Zijlstra (Intel) <[e-mail]>
Signed-off-by: Ingo Molnar <[e-mail]>
Reviewed-by: Vincent Guittot <[e-mail]>
Link: https://lkml.kernel.org/r/50cd6f[e-mail]

kernel/sched/core.c

···
 	return ret;
 }
 
-/**
- * sys_sched_yield - yield the current processor to other threads.
- *
- * This function yields the current CPU to other tasks. If there are no
- * other threads running on this CPU then this function will return.
- *
- * Return: 0.
- */
 static void do_sched_yield(void)
 {
 	struct rq_flags rf;
···
 	schedule();
 }
 
+/**
+ * sys_sched_yield - yield the current processor to other threads.
+ *
+ * This function yields the current CPU to other tasks. If there are no
+ * other threads running on this CPU then this function will return.
+ *
+ * Return: 0.
+ */
 SYSCALL_DEFINE0(sched_yield)
 {
 	do_sched_yield();

kernel/sched/fair.c

···
 }
 
 /**
- * Amount of capacity of a CPU that is (estimated to be) used by CFS tasks
+ * cpu_util - Estimates the amount of capacity of a CPU used by CFS tasks.
  * @cpu: the CPU to get the utilization of
  *
  * The unit of the return value must be the one of capacity so we can compare