spapr: fix CAS-generated reset
The OV5_MMU_RADIX_300 requires special handling in the CAS negotiation
process. It is cleared from the option vector of the guest before
evaluating the changes and re-added later. But, when testing for a
possible CAS reset :
spapr->cas_reboot = spapr_ovec_diff(ov5_updates,
ov5_cas_old, spapr->ov5_cas);
the bit OV5_MMU_RADIX_300 will each time be seen as removed from the
previous OV5 set, hence generating a reset loop.
Fix this problem by also clearing the same bit in the ov5_cas_old set.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>