rcu: Remove unused function hlist_bl_del_init_rcu()

The function hlist_bl_del_init_rcu() is declared in rculist_bl.h,
but never used.  This commit therefore removes it.
Signed-off-by: Ethan Hansen <1ethanhansen@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

include/linux/rculist_bl.h

@@ -24,34 +24,6 @@ static inline struct hlist_bl_node *hlist_bl_first_rcu(struct hlist_bl_head *h)
 		((unsigned long)rcu_dereference_check(h->first, hlist_bl_is_locked(h)) & ~LIST_BL_LOCKMASK);
 }
 
-/**
- * hlist_bl_del_init_rcu - deletes entry from hash list with re-initialization
- * @n: the element to delete from the hash list.
- *
- * Note: hlist_bl_unhashed() on the node returns true after this. It is
- * useful for RCU based read lockfree traversal if the writer side
- * must know if the list entry is still hashed or already unhashed.
- *
- * In particular, it means that we can not poison the forward pointers
- * that may still be used for walking the hash list and we can only
- * zero the pprev pointer so list_unhashed() will return true after
- * this.
- *
- * The caller must take whatever precautions are necessary (such as
- * holding appropriate locks) to avoid racing with another
- * list-mutation primitive, such as hlist_bl_add_head_rcu() or
- * hlist_bl_del_rcu(), running on this same list.  However, it is
- * perfectly legal to run concurrently with the _rcu list-traversal
- * primitives, such as hlist_bl_for_each_entry_rcu().
- */
-static inline void hlist_bl_del_init_rcu(struct hlist_bl_node *n)
-{
-	if (!hlist_bl_unhashed(n)) {
-		__hlist_bl_del(n);
-		n->pprev = NULL;
-	}
-}
-
 /**
  * hlist_bl_del_rcu - deletes entry from hash list without re-initialization
  * @n: the element to delete from the hash list.