vfio/fsl-mc: Fix the dead code in vfio_fsl_mc_set_irq_trigger

Static analysis discovered that some code in vfio_fsl_mc_set_irq_trigger
is dead code. Fixed the code by changing the conditions order.

Fixes: cc0ee20b ("vfio/fsl-mc: trigger an interrupt via eventfd")
Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Diana Craciun <diana.craciun@oss.nxp.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c

@@ -114,6 +114,9 @@ static int vfio_fsl_mc_set_irq_trigger(struct vfio_fsl_mc_device *vdev,
 	struct device *cont_dev = fsl_mc_cont_dev(&mc_dev->dev);
 	struct fsl_mc_device *mc_cont = to_fsl_mc_device(cont_dev);
 
+	if (!count && (flags & VFIO_IRQ_SET_DATA_NONE))
+		return vfio_set_trigger(vdev, index, -1);
+
 	if (start != 0 || count != 1)
 		return -EINVAL;
 
@@ -128,9 +131,6 @@ static int vfio_fsl_mc_set_irq_trigger(struct vfio_fsl_mc_device *vdev,
 		goto unlock;
 	mutex_unlock(&vdev->reflck->lock);
 
-	if (!count && (flags & VFIO_IRQ_SET_DATA_NONE))
-		return vfio_set_trigger(vdev, index, -1);
-
 	if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
 		s32 fd = *(s32 *)data;