`from_u16_until_nul` returns unnameable error type `FromSliceUntilNulError`

[MolotovCherry]

from_u16_until_nul() is returning error FromSliceUntilNulError, but this type is not publicly exported, leaving library users unable to do things like store the error type in other error types (i.e. snafu) or match against it

[phip1611]

Thanks! Nice find! Feel free to raise a PR