uwb: uwbd() is not freezable kthread

uwbd() calls try_to_freeze(), but the thread doesn't mark itself freezable
through set_freezable(), so the try_to_freeze() call is useless.

Signed-off-by: Jiri Kosina <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/uwb/uwbd.c

···
 			HZ);
 		if (should_stop)
 			break;
-		try_to_freeze();
 
 		spin_lock_irqsave(&rc->uwbd.event_list_lock, flags);
 		if (!list_empty(&rc->uwbd.event_list)) {