When mounting with smb2/smb3 (e.g. vers=2.1) and cifsacl mount option,
it was trying to get the mode by querying the acl over the cifs
rather than smb2 protocol.  This patch makes that protocol
independent and makes cifsacl smb2 mounts return a more intuitive
operation not supported error (until we add a worker function
for smb2_get_acl).

Note that a previous patch fixed getxattr/setxattr for the CIFSACL xattr
which would unconditionally call cifs_get_acl and cifs_set_acl (even when
mounted smb2). I made those protocol independent last week (new protocol
version operations "get_acl" and "set_acl" but did not add an
smb2_get_acl and smb2_set_acl yet so those now simply return EOPNOTSUPP
which at least is better than sending cifs requests on smb2 mount)

The previous patches did not fix the one remaining case though ie
mounting with "cifsacl" when getting mode from acl would unconditionally
end up calling "cifs_get_acl_from_fid" even for smb2 - so made that protocol
independent but to make that protocol independent had to make sure that the callers
were passing the protocol independent handle structure (cifs_fid) instead
of cifs specific _u16 network file handle (ie cifs_fid instead of cifs_fid->fid)

Now mount with smb2 and cifsacl mount options will return EOPNOTSUP (instead
of timing out) and a future patch will add smb2 operations (e.g. get_smb2_acl)
to enable this.
Signed-off-by: Steve French <smfrench@gmail.com>