rtla/osnoise: Set OSNOISE_WORKLOAD to true

If running rtla osnoise with NO_OSNOISE_WORKLOAD, it reports no samples:

$ echo NO_OSNOISE_WORKLOAD > /sys/kernel/tracing/osnoise/options
$ rtla osnoise hist -d 10s
Index
over: 0
count: 0
min: 0
avg: 0
max: 0

This situation can also happen when running rtla-osnoise after an
improperly exited rtla-timerlat run.

Set OSNOISE_WORKLOAD in rtla-osnoise, too, similarly to what we
already did for timerlat in commit 217f0b1 ("rtla/timerlat_top: Set
OSNOISE_WORKLOAD for kernel threads") and commit d8d8661
("rtla/timerlat_hist: Set OSNOISE_WORKLOAD for kernel threads").

Note that there is no user workload mode for rtla-osnoise yet, so
OSNOISE_WORKLOAD is always set to true.

Cc: Luis Goncalves <lgoncalv@redhat.com>
Link: https://lore.kernel.org/20250320092500.101385-4-tglozar@redhat.com
Fixes: 1eceb2f ("rtla/osnoise: Add osnoise top mode")
Fixes: 829a6c0 ("rtla/osnoise: Add the hist mode")
Signed-off-by: Tomas Glozar <tglozar@redhat.com>
Reviewed-by: John Kacur <jkacur@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

tools/tracing/rtla/src/osnoise.c

@@ -1187,6 +1187,12 @@ osnoise_apply_config(struct osnoise_tool *tool, struct osnoise_params *params)
 		auto_house_keeping(&params->monitored_cpus);
 	}
 
+	retval = osnoise_set_workload(tool->context, true);
+	if (retval < -1) {
+		err_msg("Failed to set OSNOISE_WORKLOAD option\n");
+		goto out_err;
+	}
+
 	return 0;
 
 out_err: