tracing: Use ring_buffer_record_is_set_on() in tracer_tracing_is_on()

tracer_tracing_is_on() checks whether record_disabled is not zero. This
checks both the record_disabled counter and the RB_BUFFER_OFF flag.
Reading the source it looks like this function should only check for
the RB_BUFFER_OFF flag. Therefore use ring_buffer_record_is_set_on().
This fixes spurious fails in the 'test for function traceon/off triggers'
test from the ftrace testsuite when the system is under load.

Link: https://lore.kernel.org/linux-trace-kernel/20240205065340.2848065-1-svens@linux.ibm.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Tested-By: Mete Durlu <meted@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

kernel/trace/trace.c

@@ -1532,7 +1532,7 @@ void disable_trace_on_warning(void)
 bool tracer_tracing_is_on(struct trace_array *tr)
 {
 	if (tr->array_buffer.buffer)
-		return ring_buffer_record_is_on(tr->array_buffer.buffer);
+		return ring_buffer_record_is_set_on(tr->array_buffer.buffer);
 	return !tr->buffer_disabled;
 }