sporadic deadlock fix

move to always kthreaded and mitigate sporadic deadlocks on

Co-authored-by: backslashxx <118538522+backslashxx@users.noreply.github.com>

kernel/apk_sign.c

@@ -259,7 +259,7 @@ static bool has_v1_signature_file(struct file *fp)
  * possibly optional
  *
  */
-static bool is_lock_held(const char *path) 
+bool is_lock_held(const char *path) 
 {
 	struct path kpath;