tools/tracing/rtla: osnoise_hist: display average with two-digit precision

Calculate average value in osnoise-hist summary with two-digit
precision to avoid displaying too optimitic results.

Link: https://lkml.kernel.org/r/20230103103400.275566-3-br015@umbiko.net

Signed-off-by: Andreas Ziegler <br015@umbiko.net>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

tools/tracing/rtla/src/osnoise_hist.c

@@ -335,8 +335,8 @@ osnoise_print_summary(struct osnoise_hist_params *params,
 			continue;
 
 		if (data->hist[cpu].count)
-			trace_seq_printf(trace->seq, "%9llu ",
-					data->hist[cpu].sum_sample / data->hist[cpu].count);
+			trace_seq_printf(trace->seq, "%9.2f ",
+				((double) data->hist[cpu].sum_sample) / data->hist[cpu].count);
 		else
 			trace_seq_printf(trace->seq, "        - ");
 	}