net: Simplify RX queue allocation

This patch move RX queue allocation to alloc_netdev_mq and freeing of
the queues to free_netdev (symmetric to TX queue allocation).  Each
kobject RX queue takes a reference to the queue's device so that the
device can't be freed before all the kobjects have been released-- this
obviates the need for reference counts specific to RX queues.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index a5ff5a8..3ba526b 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -706,7 +706,6 @@
 static void rx_queue_release(struct kobject *kobj)
 {
 	struct netdev_rx_queue *queue = to_rx_queue(kobj);
-	struct netdev_rx_queue *first = queue->first;
 	struct rps_map *map;
 	struct rps_dev_flow_table *flow_table;
 
@@ -719,8 +718,7 @@
 	if (flow_table)
 		call_rcu(&flow_table->rcu, rps_dev_flow_table_release);
 
-	if (atomic_dec_and_test(&first->count))
-		kfree(first);
+	dev_put(queue->dev);
 }
 
 static struct kobj_type rx_queue_ktype = {
@@ -732,7 +730,6 @@
 static int rx_queue_add_kobject(struct net_device *net, int index)
 {
 	struct netdev_rx_queue *queue = net->_rx + index;
-	struct netdev_rx_queue *first = queue->first;
 	struct kobject *kobj = &queue->kobj;
 	int error = 0;
 
@@ -745,7 +742,7 @@
 	}
 
 	kobject_uevent(kobj, KOBJ_ADD);
-	atomic_inc(&first->count);
+	dev_hold(queue->dev);
 
 	return error;
 }