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/caif/cfmuxl.c b/net/caif/cfmuxl.c
index c23979e..b36f24a 100644
--- a/net/caif/cfmuxl.c
+++ b/net/caif/cfmuxl.c
@@ -108,7 +108,7 @@
 	int idx = phyid % DN_CACHE_SIZE;
 
 	spin_lock_bh(&muxl->transmit_lock);
-	rcu_assign_pointer(muxl->dn_cache[idx], NULL);
+	RCU_INIT_POINTER(muxl->dn_cache[idx], NULL);
 	dn = get_from_id(&muxl->frml_list, phyid);
 	if (dn == NULL)
 		goto out;
@@ -164,7 +164,7 @@
 	if (up == NULL)
 		goto out;
 
-	rcu_assign_pointer(muxl->up_cache[idx], NULL);
+	RCU_INIT_POINTER(muxl->up_cache[idx], NULL);
 	list_del_rcu(&up->node);
 out:
 	spin_unlock_bh(&muxl->receive_lock);
@@ -261,7 +261,7 @@
 
 				idx = layer->id % UP_CACHE_SIZE;
 				spin_lock_bh(&muxl->receive_lock);
-				rcu_assign_pointer(muxl->up_cache[idx], NULL);
+				RCU_INIT_POINTER(muxl->up_cache[idx], NULL);
 				list_del_rcu(&layer->node);
 				spin_unlock_bh(&muxl->receive_lock);
 			}