spapr: Correct inverted test in spapr_pc_dimm_node()

spapr: Correct inverted test in spapr_pc_dimm_node()

This function was introduced between v2.11 and v2.12 to replace obsolete
ways of specifying the NUMA nodes for DIMMs.  It's used to find the correct
node for an LMB, by locating which DIMM object it lies within.

Unfortunately, one of the checks is inverted, so we check whether the
address is less than two different things, rather than actually checking
a range.  This introduced a regression, meaning that after a reboot qemu
will advertise incorrect node information for memory to the guest.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>