tracing: Remove unneeded check of max_tr->buffer before tracing_reset

There's now a check in tracing_reset_online_cpus() if the buffer is
allocated or NULL. No need to do a check before calling it with max_tr.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

kernel/trace/trace.c

@@ -4040,8 +4040,7 @@ static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf,
 	 * Reset the buffer so that it doesn't have incomparable timestamps.
 	 */
 	tracing_reset_online_cpus(&global_trace);
-	if (max_tr.buffer)
-		tracing_reset_online_cpus(&max_tr);
+	tracing_reset_online_cpus(&max_tr);
 
 	mutex_unlock(&trace_types_lock);