spapr_core_pre_plug() already guarantees that the slot for the given core
ID is available. It is thus safe to assume that spapr_find_cpu_slot()
returns a slot during plug. Turn the error path into an assertion.
It is also safe to assume that no device is attached to the corresponding
DRC and that spapr_drc_attach() shouldn't fail.
Pass &error_abort to spapr_drc_attach() and simplify error handling.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20201201113728.885700-4-groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>