KVM: arm: vgic: Drop build compatibility hack for older kernel versions

As kvm_set_routing_entry() was changing prototype between 4.7 and 4.8,
an ugly hack was put in place in order to survive both building in
-next and the merge window.

Now that everything has been merged, let's dump the compatibility
hack for good.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

virt/kvm/arm/vgic/vgic-irqfd.c

@@ -46,15 +46,9 @@ static int vgic_irqfd_set_irq(struct kvm_kernel_irq_routing_entry *e,
  * @ue: user api routing entry handle
  * return 0 on success, -EINVAL on errors.
  */
-#ifdef KVM_CAP_X2APIC_API
 int kvm_set_routing_entry(struct kvm *kvm,
 			  struct kvm_kernel_irq_routing_entry *e,
 			  const struct kvm_irq_routing_entry *ue)
-#else
-/* Remove this version and the ifdefery once merged into 4.8 */
-int kvm_set_routing_entry(struct kvm_kernel_irq_routing_entry *e,
-			  const struct kvm_irq_routing_entry *ue)
-#endif
 {
 	int r = -EINVAL;