KVM: i8254: remove pointless dereference of PIT

PIT is known at that point.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/i8254.c

@@ -267,8 +267,8 @@ static void pit_do_work(struct kthread_work *work)
 	if (ps->reinject && !atomic_xchg(&ps->irq_ack, 0))
 		return;
 
-	kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 1, false);
-	kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 0, false);
+	kvm_set_irq(kvm, pit->irq_source_id, 0, 1, false);
+	kvm_set_irq(kvm, pit->irq_source_id, 0, 0, false);
 
 	/*
 	 * Provides NMI watchdog support via Virtual Wire mode.