ipoe: T6205: fix conditional branch error in config migrator
Commit a5ccc06c0 ("ipoe: T6205: error in migration script logic while renaming
mac-address to mac node") added a conditional path into the config which could
result in the migrated config not beeing written if precondition was not met.
(cherry picked from commit 2bbded1e485614d40b2e95165629487537fd1757)