KVM: clean up directives to compile out irqfds

Keep all #ifdef CONFIG_HAVE_KVM_IRQCHIP parts of eventfd.c together, and
compile out the irqfds field of struct kvm if the symbol is not defined.

Signed-off-by: Paolo Bonzini <[e-mail]>

include/linux/kvm_host.h

···
 	struct list_head vm_list;
 	struct mutex lock;
 	struct kvm_io_bus __rcu *buses[KVM_NR_BUSES];
+#ifdef CONFIG_HAVE_KVM_IRQCHIP
 	struct {
 		spinlock_t        lock;
 		struct list_head  items;
···
 		struct list_head  resampler_list;
 		struct mutex      resampler_lock;
 	} irqfds;
+#endif
 	struct list_head ioeventfds;
 	struct kvm_vm_stat stat;
 	struct kvm_arch arch;

virt/kvm/eventfd.c

···
 	synchronize_srcu(&kvm->irq_srcu);
 	kvm_arch_post_irq_ack_notifier_list_update(kvm);
 }
-#endif
 
-void
-kvm_eventfd_init(struct kvm *kvm)
-{
-#ifdef CONFIG_HAVE_KVM_IRQCHIP
-	spin_lock_init(&kvm->irqfds.lock);
-	INIT_LIST_HEAD(&kvm->irqfds.items);
-	INIT_LIST_HEAD(&kvm->irqfds.resampler_list);
-	mutex_init(&kvm->irqfds.resampler_lock);
-#endif
-	INIT_LIST_HEAD(&kvm->ioeventfds);
-}
-
-#ifdef CONFIG_HAVE_KVM_IRQCHIP
 /*
  * shutdown any irqfd's that match fd+gsi
  */
···
 		return kvm_deassign_ioeventfd(kvm, args);
 
 	return kvm_assign_ioeventfd(kvm, args);
+}
+
+void
+kvm_eventfd_init(struct kvm *kvm)
+{
+#ifdef CONFIG_HAVE_KVM_IRQCHIP
+	spin_lock_init(&kvm->irqfds.lock);
+	INIT_LIST_HEAD(&kvm->irqfds.items);
+	INIT_LIST_HEAD(&kvm->irqfds.resampler_list);
+	mutex_init(&kvm->irqfds.resampler_lock);
+#endif
+	INIT_LIST_HEAD(&kvm->ioeventfds);
 }