[NET]: Fix spurious kfree and missed initialization in TUN driver.

drivers/net/tun.c

@@ -404,6 +404,7 @@ static int tun_set_iff(struct file *file, struct ifreq *ifr)
 			return -ENOMEM;
 
 		tun = dev->priv;
+		tun->dev = dev;
 		tun->flags = flags;
 
 		if (strchr(dev->name, '%')) {
@@ -566,8 +567,6 @@ static int tun_chr_close(struct inode *inode, struct file *file)
 
 	rtnl_unlock();
 
-	if (!(tun->flags & TUN_PERSIST)) 
-		kfree(tun);
 	return 0;
 }