[PATCH] net: switchdev: fix return code of fdb_dump stub

[Dragos Tatulea <dragos@endocode.com>]

rtnl_fdb_dump always expects an index to be returned by the ndo_fdb_dump op,
but when CONFIG_NET_SWITCHDEV is off, it returns an error.

Fix that by returning the given unmodified idx.

A similar fix was 0890cf6cb6ab ("switchdev: fix return value of
switchdev_port_fdb_dump in case of error") but for the CONFIG_NET_SWITCHDEV=y
case.

Fixes: 45d4122ca7cd ("switchdev: add support for fdb add/del/dump via switchdev_port_obj ops.")
Signed-off-by: Dragos Tatulea <dragos@endocode.com>
---
 include/net/switchdev.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/net/switchdev.h b/include/net/switchdev.h
index bc865e2..bc5765a 100644
--- a/include/net/switchdev.h
+++ b/include/net/switchdev.h
@@ -323,7 +323,7 @@ static inline int switchdev_port_fdb_dump(struct sk_buff *skb,
                                          struct net_device *filter_dev,
                                          int idx)
 {
-       return -EOPNOTSUPP;
+       return idx;
 }
 
 static inline void switchdev_port_fwd_mark_set(struct net_device *dev,