[RFC PATCH mcgrof-next] hung_task: sysctl_hung_task_all_cpu_backtrace can be static

[kernel test robot]

kernel/hung_task.c:66:28: warning: symbol 'sysctl_hung_task_all_cpu_backtrace' was not declared. Should it be static?

Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: kernel test robot <lkp@xxxxxxxxx>
---
 hung_task.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index edccc9a09a62f..cf16ddc02f503 100644
--- a/kernel/hung_task.c
+++ b/kernel/hung_task.c
@@ -63,7 +63,7 @@ static struct task_struct *watchdog_task;
  * Should we dump all CPUs backtraces in a hung task event?
  * Defaults to 0, can be changed via sysctl.
  */
-unsigned int __read_mostly sysctl_hung_task_all_cpu_backtrace;
+static unsigned int __read_mostly sysctl_hung_task_all_cpu_backtrace;
 #else
 /* Avoid need for ifdefs elsewhere in the code */
 enum { sysctl_hung_task_timeout_secs = 0 };