tracing/osnoise: Make osnoise_instances static

Make the struct list_head osnoise_instances definition static.

Link: https://lore.kernel.org/all/202111120052.ZuikQSJi-lkp@intel.com/
Link: https://lkml.kernel.org/r/d001f0eeac66e2b2eeec7d2a15e9e7abede0453a.1636667971.git.bristot@kernel.org

Cc: Ingo Molnar <mingo@redhat.com>
Fixes: dae18134 ("tracing/osnoise: Support a list of trace_array *tr")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

kernel/trace/trace_osnoise.c

@@ -55,7 +55,8 @@ struct osnoise_instance {
 	struct list_head	list;
 	struct trace_array	*tr;
 };
-struct list_head osnoise_instances;
+
+static struct list_head osnoise_instances;
 
 static bool osnoise_has_registered_instances(void)
 {