mode bits in libsmb_stat are fairly cheaply constructed. file and directory
qualification is alright beyond that it is a bit of a shambles.
specifically +W is set iff the DOS attribute READONLY isn't set, but
that attribute doesn't mean what we think it means, at least not on
NT+ systems. see exhaustive comment.
long story short: we cannot represent mode bits accurately because NT's
access controls simply do not map to posix mode bits. therefore I'm
removing the mode setting for the udsentry, making all entries effectively
whether an entry truly is writable is hard to say anyway. specifically
because SMB+NTFS have independent ACLs. so, the SMB ACL may allow a
given user or group to do something, that doesn't mean they'll also
have permissions on a file system level.