rtla/timerlat: Simplify "no value" printing on top

Instead of printing three times the same output, print it only once,
reducing lines and being sure that all no values have the same length.

It also fixes an extra '\n' when running the with kernel threads, like
here:

     =============== %< ==============
                                      Timer Latency

   0 00:00:01   |          IRQ Timer Latency (us)        |         Thread Timer Latency (us)
 CPU COUNT      |      cur       min       avg       max |      cur       min       avg       max
   2 #0         |        -         -         -         - |      161       161       161       161
   3 #0         |        -         -         -         - |      161       161       161       161
   8 #1         |       54        54        54        54 |        -         -         -         -'\n'

 ---------------|----------------------------------------|---------------------------------------
 ALL #1      e0 |                 54        54        54 |                161       161       161
     =============== %< ==============

This '\n' should have been removed with the user-space support that
added another '\n' if not running with kernel threads.

Link: https://lkml.kernel.org/r/0a4d8085e7cd706733a5dc10a81ca38b82bd4992.1713968967.git.bristot@kernel.org

Cc: [email protected]
Cc: Jonathan Corbet <[email protected]>
Cc: Juri Lelli <[email protected]>
Fixes: cdca4f4 ("rtla/timerlat_top: Add timerlat user-space support")
Signed-off-by: Daniel Bristot de Oliveira <[email protected]>

Author: Daniel Bristot de Oliveira

tools/tracing/rtla/src/timerlat_top.c

@@ -212,6 +212,8 @@ static void timerlat_top_header(struct osnoise_tool *top)
 	trace_seq_printf(s, "\n");
 }
 
+static const char *no_value = "        -";
+
 /*
  * timerlat_top_print - prints the output of a given CPU
  */
@@ -239,10 +241,7 @@ static void timerlat_top_print(struct osnoise_tool *top, int cpu)
 	trace_seq_printf(s, "%3d #%-9d |", cpu, cpu_data->irq_count);
 
 	if (!cpu_data->irq_count) {
-		trace_seq_printf(s, "        - ");
-		trace_seq_printf(s, "        - ");
-		trace_seq_printf(s, "        - ");
-		trace_seq_printf(s, "        - |");
+		trace_seq_printf(s, "%s %s %s %s |", no_value, no_value, no_value, no_value);
 	} else {
 		trace_seq_printf(s, "%9llu ", cpu_data->cur_irq / params->output_divisor);
 		trace_seq_printf(s, "%9llu ", cpu_data->min_irq / params->output_divisor);
@@ -251,10 +250,7 @@ static void timerlat_top_print(struct osnoise_tool *top, int cpu)
 	}
 
 	if (!cpu_data->thread_count) {
-		trace_seq_printf(s, "        - ");
-		trace_seq_printf(s, "        - ");
-		trace_seq_printf(s, "        - ");
-		trace_seq_printf(s, "        -\n");
+		trace_seq_printf(s, "%s %s %s %s", no_value, no_value, no_value, no_value);
 	} else {
 		trace_seq_printf(s, "%9llu ", cpu_data->cur_thread / divisor);
 		trace_seq_printf(s, "%9llu ", cpu_data->min_thread / divisor);
@@ -271,10 +267,7 @@ static void timerlat_top_print(struct osnoise_tool *top, int cpu)
 	trace_seq_printf(s, " |");
 
 	if (!cpu_data->user_count) {
-		trace_seq_printf(s, "        - ");
-		trace_seq_printf(s, "        - ");
-		trace_seq_printf(s, "        - ");
-		trace_seq_printf(s, "        -\n");
+		trace_seq_printf(s, "%s %s %s %s\n", no_value, no_value, no_value, no_value);
 	} else {
 		trace_seq_printf(s, "%9llu ", cpu_data->cur_user / divisor);
 		trace_seq_printf(s, "%9llu ", cpu_data->min_user / divisor);