snull: fix error handling in device registeration

If the first device registration fails, the second iteration of the loop
will set the ret to zero. Also, jumping to snull_cleanup() will put the
device into unreg queue which is unnecessary.

snull/snull.c

@@ -752,28 +752,29 @@ static void snull_cleanup(void)
 
 static int snull_init_module(void)
 {
-	int result, i, ret = -ENOMEM;
+	int result, i, ret = 0;
 
 	snull_interrupt = use_napi ? snull_napi_interrupt : snull_regular_interrupt;
 
-	/* Allocate the devices */
-	snull_devs[0] = alloc_netdev(sizeof(struct snull_priv), "sn%d",
-			NET_NAME_UNKNOWN, snull_init);
-	snull_devs[1] = alloc_netdev(sizeof(struct snull_priv), "sn%d",
+	/* Allocate and register the devices */
+	for (i = 0; i < 2;  i++) {
+		snull_devs[i] = alloc_netdev(sizeof(struct snull_priv), "sn%d",
 			NET_NAME_UNKNOWN, snull_init);
-	if (snull_devs[0] == NULL || snull_devs[1] == NULL)
-		goto out;
 
-	ret = -ENODEV;
-	for (i = 0; i < 2;  i++)
-		if ((result = register_netdev(snull_devs[i])))
+		if (snull_devs[i] == NULL) {
+			ret = -ENOMEM;
+			break;
+		}
+
+		if ((result = register_netdev(snull_devs[i]))) {
 			printk("snull: error %i registering device \"%s\"\n",
 					result, snull_devs[i]->name);
-		else
-			ret = 0;
-   out:
-	if (ret) 
-		snull_cleanup();
+			free_netdev(snull_devs[i]);
+			ret = -ENODEV;
+			break;
+		}
+	}
+
 	return ret;
 }