acpi: Assert sts array limit on AcpiCpuHotplug_add()

AcpiCpuHotplug_add() can't handle vCPU arch IDs larger than
ACPI_CPU_HOTPLUG_ID_LIMIT. Instead of corrupting memory in case the vCPU
ID is too large, use g_assert() to ensure we are not over the limit.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
