net: core: dev_get_valid_name is now the same as dev_alloc_name_ns

If name contains a %, it's easy to see that this patch doesn't change
anything (other than eliminate the duplicate dev_valid_name
call). Otherwise, we'll now just spend a little time in snprintf()
copying name to the stack buffer allocated in dev_alloc_name_ns, and do
the __dev_get_by_name using that buffer rather than name.
Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/core/dev.c

@@ -1146,19 +1146,7 @@ EXPORT_SYMBOL(dev_alloc_name);
 int dev_get_valid_name(struct net *net, struct net_device *dev,
 		       const char *name)
 {
-	BUG_ON(!net);
-
-	if (!dev_valid_name(name))
-		return -EINVAL;
-
-	if (strchr(name, '%'))
-		return dev_alloc_name_ns(net, dev, name);
-	else if (__dev_get_by_name(net, name))
-		return -EEXIST;
-	else if (dev->name != name)
-		strlcpy(dev->name, name, IFNAMSIZ);
-
-	return 0;
+	return dev_alloc_name_ns(net, dev, name);
 }
 EXPORT_SYMBOL(dev_get_valid_name);