kthread: unexport __kthread_should_park()

There are no in-kernel users of __kthread_should_park() so mark it as
static and do not export it.

Link: https://lkml.kernel.org/r/2023080450-handcuff-stump-1d6e@gregkhSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: John Stultz <jstultz@google.com>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: "Arve Hjønnevåg" <arve@android.com>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Christian Brauner (Microsoft)" <brauner@kernel.org>
Cc: Mike Christie <michael.christie@oracle.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Zqiang <qiang1.zhang@intel.com>
Cc: Prathu Baronia <quic_pbaronia@quicinc.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/linux/kthread.h

@@ -88,7 +88,6 @@ void kthread_bind_mask(struct task_struct *k, const struct cpumask *mask);
 int kthread_stop(struct task_struct *k);
 bool kthread_should_stop(void);
 bool kthread_should_park(void);
-bool __kthread_should_park(struct task_struct *k);
 bool kthread_should_stop_or_park(void);
 bool kthread_freezable_should_stop(bool *was_frozen);
 void *kthread_func(struct task_struct *k);

kernel/kthread.c

@@ -159,11 +159,10 @@ bool kthread_should_stop(void)
 }
 EXPORT_SYMBOL(kthread_should_stop);
 
-bool __kthread_should_park(struct task_struct *k)
+static bool __kthread_should_park(struct task_struct *k)
 {
 	return test_bit(KTHREAD_SHOULD_PARK, &to_kthread(k)->flags);
 }
-EXPORT_SYMBOL_GPL(__kthread_should_park);
 
 /**
  * kthread_should_park - should this kthread park now?