tracing/timerlat: Do not wakeup the thread if the trace stops at the IRQ

There is no need to wakeup the timerlat/ thread if stop tracing is hit
at the timerlat's IRQ handler.

Return before waking up timerlat's thread.

Link: https://lkml.kernel.org/r/b392356c91b56aedd2b289513cc56a84cf87e60d.1652175637.git.bristot@kernel.org

Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

kernel/trace/trace_osnoise.c

@@ -1595,6 +1595,8 @@ static enum hrtimer_restart timerlat_irq(struct hrtimer *timer)
 
 			osnoise_stop_tracing();
 			notify_new_max_latency(diff);
+
+			return HRTIMER_NORESTART;
 		}
 	}