perf stat: Don't display zero tool counts

Andi reported (see link below) a regression when printing the
'duration_time' tool event, where it gets printed as "not counted" for
most of the CPUs, fix it by skipping zero counts for tool events.

Reported-by: Andi Kleen <[email protected]>
Signed-off-by: Ian Rogers <[email protected]>
Tested-by: Andi Kleen <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Athira Rajeev <[email protected]>
Cc: Claire Jensen <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: https://lore.kernel.org/all/ZMlrzcVrVi1lTDmn@tassilo/
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: captain5050

tools/perf/util/stat-display.c

@@ -931,6 +931,11 @@ static bool should_skip_zero_counter(struct perf_stat_config *config,
 	 */
 	if (config->aggr_mode == AGGR_THREAD && config->system_wide)
 		return true;
+
+	/* Tool events have the software PMU but are only gathered on 1. */
+	if (evsel__is_tool(counter))
+		return true;
+
 	/*
 	 * Skip value 0 when it's an uncore event and the given aggr id
 	 * does not belong to the PMU cpumask.