cifs: return -ENODATA when deleting an xattr that does not exist

cifs: return -ENODATA when deleting an xattr that does not exist

BUGZILLA: https://bugzilla.kernel.org/show_bug.cgi?id=202007

When deleting an xattr/EA:
SMB2/3 servers will return SUCCESS when clients delete non-existing EAs.
This means that we need to first QUERY the server and check if the EA
exists or not so that we can return -ENODATA correctly when this happens.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>