rcu: convert uses of rcu_assign_pointer(x, NULL) to RCU_INIT_POINTER

When assigning a NULL value to an RCU protected pointer, no barrier
is needed. The rcu_assign_pointer, used to handle that but will soon
change to not handle the special case.

Convert all rcu_assign_pointer of NULL value.

//smpl
@@ expression P; @@

- rcu_assign_pointer(P, NULL)
+ RCU_INIT_POINTER(P, NULL)

// </smpl>

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index de9e297..89d6f71 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -204,7 +204,7 @@
 	return (struct tnode *)(parent & ~NODE_TYPE_MASK);
 }
 
-/* Same as rcu_assign_pointer
+/* Same as RCU_INIT_POINTER
  * but that macro() assumes that value is a pointer.
  */
 static inline void node_set_parent(struct rt_trie_node *node, struct tnode *ptr)
@@ -528,7 +528,7 @@
 	if (n)
 		node_set_parent(n, tn);
 
-	rcu_assign_pointer(tn->child[i], n);
+	RCU_INIT_POINTER(tn->child[i], n);
 }
 
 #define MAX_WORK 10
@@ -1014,7 +1014,7 @@
 
 		tp = node_parent((struct rt_trie_node *) tn);
 		if (!tp)
-			rcu_assign_pointer(t->trie, (struct rt_trie_node *)tn);
+			RCU_INIT_POINTER(t->trie, (struct rt_trie_node *)tn);
 
 		tnode_free_flush();
 		if (!tp)
@@ -1026,7 +1026,7 @@
 	if (IS_TNODE(tn))
 		tn = (struct tnode *)resize(t, (struct tnode *)tn);
 
-	rcu_assign_pointer(t->trie, (struct rt_trie_node *)tn);
+	RCU_INIT_POINTER(t->trie, (struct rt_trie_node *)tn);
 	tnode_free_flush();
 }
 
@@ -1163,7 +1163,7 @@
 			put_child(t, (struct tnode *)tp, cindex,
 				  (struct rt_trie_node *)tn);
 		} else {
-			rcu_assign_pointer(t->trie, (struct rt_trie_node *)tn);
+			RCU_INIT_POINTER(t->trie, (struct rt_trie_node *)tn);
 			tp = tn;
 		}
 	}
@@ -1621,7 +1621,7 @@
 		put_child(t, (struct tnode *)tp, cindex, NULL);
 		trie_rebalance(t, tp);
 	} else
-		rcu_assign_pointer(t->trie, NULL);
+		RCU_INIT_POINTER(t->trie, NULL);
 
 	free_leaf(l);
 }