Augustin Cavalier
9708b08060
B_PATH_NAME_LENGTH == PATH_MAX, and PATH_MAX is inclusive of the final
NULL terminator, so we don't need a + 1 here.
The original KPath default was to not use + 1, but that was changed in
42e3c6f978 due to all the consumers that did.
But all those consumers are wrong, it appears; they should just be
using the default length instead. So now we do that.