kvm_arch_load_regs() might load APIC base and APIC TPR from the
uninitialized userspace APIC emulation.

This happened when running X11 on SMP guest in my case, disabling the
APIC for vcpu3:

vcpu not ready for apic_round_robin
vcpu not ready for apic_round_robin
vcpu not ready for apic_round_robin
...

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>