tick/sched: Fix non-kernel-doc comment

Fixes the following W=1 kernel build warning:

kernel/time/tick-sched.c:1563: warning: This comment starts with '/**',
but isn't a kernel-doc comment.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220214084739.63228-1-jiapeng.chong@linux.alibaba.com

kernel/time/tick-sched.c

@@ -1538,7 +1538,7 @@ void tick_cancel_sched_timer(int cpu)
 }
 #endif
 
-/**
+/*
  * Async notification about clocksource changes
  */
 void tick_clock_notify(void)
@@ -1559,7 +1559,7 @@ void tick_oneshot_notify(void)
 	set_bit(0, &ts->check_clocks);
 }
 
-/**
+/*
  * Check, if a change happened, which makes oneshot possible.
  *
  * Called cyclic from the hrtimer softirq (driven by the timer