nvd compatibility links and geli

From: Stefan Ehmann <shoesoft_at_gmx.net>
Date: Sat, 23 Sep 2023 13:18:44 UTC
The 20230612 entry in UPDATING says:

        Encrypted swap partitions need to be changed from nvd to nda if you
        migrate, or you need to use the above to switch back to nvd.

Are encrypted (non-swap) partitions supposed to work? If not, it would be less
confusing to directly abort with an error message instead of prompting "Enter
passphrase: " first.

# ls -l /dev/nvd0p4
lrwxr-xr-x  1 root wheel 6 Sep 23 14:59 /dev/nvd0p4 -> nda0p4
# geli attach nvd0p4
Enter passphrase:
geli: Provider not found: "nvd0p4"
geli: There was an error with at least one provider.

Using nda works as expected:
# geli attach nda0p4
# Enter passphrase:
<no error>

Tested on 14.0-BETA3.