Incorrect error returned on setting file compressed on SMB2

Incorrect error returned on setting file compressed on SMB2

When the server (for an SMB2 or SMB3 mount) doesn't support
an ioctl (such as setting the compressed flag
on a file) we were incorrectly returning EIO instead
of EOPNOTSUPP, this is confusing e.g. doing chattr +c to a file
on a non-btrfs Samba partition, now the error returned is more
intuitive to the user.  Also fixes error mapping on setting
hardlink to servers which don't support that.

Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: David Disseldorp <ddiss@suse.de>