The need for -o was introduced in db6aeda to set the -p flag for login.
Setting -o overrides agettys built-in handling of arguments, so "-- \\u" was needed to mimic it.
This broke the autologin-feature, since the -f (noauth) flag is not passed to login [1].
But with 3d2157e, the -p flag is dropped, but the full change wasn't reverted,
leaving autologin still broken - But for no reason since agetty does the right thing.
Reference:
[1]: https://github.com/util-linux/util-linux/blob/4e14b57/term-utils/agetty.c#L529-L550
