I can't see a reason why these shouldn't work on every group.  However,
they only seem to work on named groups.  This patch allows the group
functions to work on anonymous groups (those with NULL names).
Acked-by: NTejun Heo <htejun@gmail.com>
Acked-by: NKay Sievers <kay.sievers@vrfy.org>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>