net: core: eliminate dev_alloc_name{,_ns} code duplication

dev_alloc_name contained a BUG_ON(), which I moved to dev_alloc_name_ns;
the only other caller of that already has the same BUG_ON.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/dev.c

@@ -1114,6 +1114,7 @@ static int dev_alloc_name_ns(struct net *net,
 	char buf[IFNAMSIZ];
 	int ret;
 
+	BUG_ON(!net);
 	ret = __dev_alloc_name(net, name, buf);
 	if (ret >= 0)
 		strlcpy(dev->name, buf, IFNAMSIZ);
@@ -1136,16 +1137,7 @@ static int dev_alloc_name_ns(struct net *net,
 
 int dev_alloc_name(struct net_device *dev, const char *name)
 {
-	char buf[IFNAMSIZ];
-	struct net *net;
-	int ret;
-
-	BUG_ON(!dev_net(dev));
-	net = dev_net(dev);
-	ret = __dev_alloc_name(net, name, buf);
-	if (ret >= 0)
-		strlcpy(dev->name, buf, IFNAMSIZ);
-	return ret;
+	return dev_alloc_name_ns(dev_net(dev), dev, name);
 }
 EXPORT_SYMBOL(dev_alloc_name);