OK, so can't this hunk:
```
if (fdb_info->is_dyn)
fdb_flags |= DSA_FDB_FLAG_DYNAMIC;
```
Become:
```
if (fdb_info->is_dyn && !fdb_info->added_by_user)
fdb_flags |= DSA_FDB_FLAG_DYNAMIC;
```
?
Then there is no need to fold 'added_by_user' into 'is_dyn' in the
bridge driver. I *think* this is the change Vladimir asked you to do.