fusefrontend: don't return EIO on directory with corrupt file names
fusefrontend: don't return EIO on directory with corrupt file names

This was meant as a way to inform the user that
something is very wrong, however, users are hitting
the condition on MacOS due to ".DS_Store" files, and
also on NFS due to ".nfsXXX" files.

Drop the whole thing as it seems to cause more pain
than gain.

Fixes https://github.com/rfjakob/gocryptfs/issues/431

rfjakob/gocryptfs,rfjakob/gocryptfs,rfjakob/gocryptfs,rfjakob/gocryptfs