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/phonet/socket.c b/net/phonet/socket.c
index ab07711..676d18d 100644
--- a/net/phonet/socket.c
+++ b/net/phonet/socket.c
@@ -679,7 +679,7 @@
 	mutex_lock(&resource_mutex);
 	if (pnres.sk[res] == NULL) {
 		sock_hold(sk);
-		rcu_assign_pointer(pnres.sk[res], sk);
+		RCU_INIT_POINTER(pnres.sk[res], sk);
 		ret = 0;
 	}
 	mutex_unlock(&resource_mutex);
@@ -695,7 +695,7 @@
 
 	mutex_lock(&resource_mutex);
 	if (pnres.sk[res] == sk) {
-		rcu_assign_pointer(pnres.sk[res], NULL);
+		RCU_INIT_POINTER(pnres.sk[res], NULL);
 		ret = 0;
 	}
 	mutex_unlock(&resource_mutex);
@@ -714,7 +714,7 @@
 	mutex_lock(&resource_mutex);
 	for (res = 0; res < 256; res++) {
 		if (pnres.sk[res] == sk) {
-			rcu_assign_pointer(pnres.sk[res], NULL);
+			RCU_INIT_POINTER(pnres.sk[res], NULL);
 			match++;
 		}
 	}