Revert "tun: call dev_get_valid_name() before register_netdevice()"

This reverts commit 0ad646c8.

As noticed by Jakub, this is no longer needed after
commit 11fc7d5a ("tun: fix memory leak in error path")

This no longer exports dev_get_valid_name() for the exclusive
use of tun driver.
Suggested-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>

drivers/net/tun.c

@@ -2788,9 +2788,6 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 
 		if (!dev)
 			return -ENOMEM;
-		err = dev_get_valid_name(net, dev, name);
-		if (err < 0)
-			goto err_free_dev;
 
 		dev_net_set(dev, net);
 		dev->rtnl_link_ops = &tun_link_ops;

include/linux/netdevice.h

@@ -4113,9 +4113,6 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
 				    unsigned char name_assign_type,
 				    void (*setup)(struct net_device *),
 				    unsigned int txqs, unsigned int rxqs);
-int dev_get_valid_name(struct net *net, struct net_device *dev,
-		       const char *name);
-
 #define alloc_netdev(sizeof_priv, name, name_assign_type, setup) \
 	alloc_netdev_mqs(sizeof_priv, name, name_assign_type, setup, 1, 1)
 

net/core/dev.c

@@ -1249,7 +1249,7 @@ int dev_alloc_name(struct net_device *dev, const char *name)
 }
 EXPORT_SYMBOL(dev_alloc_name);
 
-int dev_get_valid_name(struct net *net, struct net_device *dev,
+static int dev_get_valid_name(struct net *net, struct net_device *dev,
 			      const char *name)
 {
 	BUG_ON(!net);
@@ -1266,7 +1266,6 @@ int dev_get_valid_name(struct net *net, struct net_device *dev,
 
 	return 0;
 }
-EXPORT_SYMBOL(dev_get_valid_name);
 
 /**
  *	dev_change_name - change name of a device