KVM: use jump label to optimize checking for in kernel local apic presence

Usually all vcpus have local apic pointer initialized, so the check may
be completely skipped.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 3d1134d..2b5219c 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -124,4 +124,5 @@
 
 extern u64 host_xcr0;
 
+extern struct static_key kvm_no_apic_vcpu;
 #endif