KVM: x86: check kvm_pit outside kvm_vm_ioctl_reinject()

check kvm_pit outside kvm_vm_ioctl_reinject() to keep codestyle consistent
with other kvm_pit func and prepare for futher cleanups.
Signed-off-by: NMiaohe Lin <linmiaohe@huawei.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/x86.c

@@ -4703,9 +4703,6 @@ static int kvm_vm_ioctl_reinject(struct kvm *kvm,
 {
 	struct kvm_pit *pit = kvm->arch.vpit;
 
-	if (!pit)
-		return -ENXIO;
-
 	/* pit->pit_state.lock was overloaded to prevent userspace from getting
 	 * an inconsistent state after running multiple KVM_REINJECT_CONTROL
 	 * ioctls in parallel.  Use a separate lock if that ioctl isn't rare.
@@ -5072,6 +5069,9 @@ long kvm_arch_vm_ioctl(struct file *filp,
 		r =  -EFAULT;
 		if (copy_from_user(&control, argp, sizeof(control)))
 			goto out;
+		r = -ENXIO;
+		if (!kvm->arch.vpit)
+			goto out;
 		r = kvm_vm_ioctl_reinject(kvm, &control);
 		break;
 	}