KVM: Avoid using x86_emulate_ctxt.vcpu

We can use container_of() instead.
Signed-off-by: NAvi Kivity <avi@redhat.com>

arch/x86/kvm/x86.c

@@ -4366,7 +4366,7 @@ static void emulator_halt(struct x86_emulate_ctxt *ctxt)
 static void emulator_get_fpu(struct x86_emulate_ctxt *ctxt)
 {
 	preempt_disable();
-	kvm_load_guest_fpu(ctxt->vcpu);
+	kvm_load_guest_fpu(emul_to_vcpu(ctxt));
 	/*
 	 * CR0.TS may reference the host fpu state, not the guest fpu state,
 	 * so it may be clear at this point.