[PATCH] devtmpfs: Add missing lockdep annotation

[Helge Deller <deller@xxxxxx>]

Add the lockdep annotation to the setup_done completer to avoid this
kernel warning:

 Backtrace:
  [<000000004030bcd0>] show_stack+0x74/0xb0
  [<000000004146c63c>] dump_stack_lvl+0x104/0x180
  [<000000004146c6ec>] dump_stack+0x34/0x48
  [<000000004040e5b4>] register_lock_class+0xd24/0xd30
  [<000000004040c21c>] __lock_acquire.isra.0+0xb4/0xac8
  [<000000004040cd60>] lock_acquire+0x130/0x298
  [<000000004147095c>] _raw_spin_lock_irq+0x60/0xb8
  [<0000000041474a4c>] wait_for_completion+0xa0/0x2d0
  [<000000004015d9f4>] devtmpfs_init+0x1e0/0x2b8
  [<000000004015d0e4>] driver_init+0x68/0x1b8
  [<0000000040102b68>] kernel_init_freeable+0x4ac/0x7f0
  [<000000004146df68>] kernel_init+0x64/0x3a8
  [<0000000040302020>] ret_from_kernel_thread+0x20/0x28

Signed-off-by: Helge Deller <deller@xxxxxx>

diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index b848764ef018..f98d58b0225c 100644
--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -462,6 +462,7 @@ int __init devtmpfs_init(void)
 		return err;
 	}

+	init_completion(&setup_done);
 	thread = kthread_run(devtmpfsd, &err, "kdevtmpfs");
 	if (!IS_ERR(thread)) {
 		wait_for_completion(&setup_done);