kernel/hung_task: unexport sysctl_hung_task_timeout_secs

This was added by the bcachefs pull requests despite various
objections, and with bcachefs removed is now unused.

This reverts commit 5c3273e.

Signed-off-by: Christoph Hellwig <[email protected]>

Author: Christoph Hellwig

kernel/hung_task.c

@@ -50,7 +50,6 @@ static unsigned long __read_mostly sysctl_hung_task_detect_count;
  * Zero means infinite timeout - no checking done:
  */
 unsigned long __read_mostly sysctl_hung_task_timeout_secs = CONFIG_DEFAULT_HUNG_TASK_TIMEOUT;
-EXPORT_SYMBOL_GPL(sysctl_hung_task_timeout_secs);
 
 /*
  * Zero (default value) means use sysctl_hung_task_timeout_secs: