KVM: VMX: Refactor update_cr8_intercept()

No functional changes.
Reviewed-by: NJoao Martins <joao.m.martins@oracle.com>
Signed-off-by: NLiran Alon <liran.alon@oracle.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx/vmx.c

@@ -5981,17 +5981,14 @@ static void vmx_l1d_flush(struct kvm_vcpu *vcpu)
 static void update_cr8_intercept(struct kvm_vcpu *vcpu, int tpr, int irr)
 {
 	struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
+	int tpr_threshold;
 
 	if (is_guest_mode(vcpu) &&
 		nested_cpu_has(vmcs12, CPU_BASED_TPR_SHADOW))
 		return;
 
-	if (irr == -1 || tpr < irr) {
-		vmcs_write32(TPR_THRESHOLD, 0);
-		return;
-	}
-
-	vmcs_write32(TPR_THRESHOLD, irr);
+	tpr_threshold = (irr == -1 || tpr < irr) ? 0 : irr;
+	vmcs_write32(TPR_THRESHOLD, tpr_threshold);
 }
 
 void vmx_set_virtual_apic_mode(struct kvm_vcpu *vcpu)