vfio/samples: Delete useless open/close

The core code no longer requires these ops to be defined, so delete these
empty functions and leave the op as NULL. mtty's functions only log a
pointless message, delete that entirely.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/5-v4-9ea22c5e6afb+1adf-vfio_reflck_jgg@nvidia.comSigned-off-by: Alex Williamson <alex.williamson@redhat.com>

samples/vfio-mdev/mbochs.c

@@ -1278,11 +1278,6 @@ static long mbochs_ioctl(struct vfio_device *vdev, unsigned int cmd,
 	return -ENOTTY;
 }
 
-static int mbochs_open(struct vfio_device *vdev)
-{
-	return 0;
-}
-
 static void mbochs_close(struct vfio_device *vdev)
 {
 	struct mdev_state *mdev_state =
@@ -1401,7 +1396,6 @@ static struct attribute_group *mdev_type_groups[] = {
 };
 
 static const struct vfio_device_ops mbochs_dev_ops = {
-	.open = mbochs_open,
 	.release = mbochs_close,
 	.read = mbochs_read,
 	.write = mbochs_write,

samples/vfio-mdev/mdpy.c

@@ -614,15 +614,6 @@ static long mdpy_ioctl(struct vfio_device *vdev, unsigned int cmd,
 	return -ENOTTY;
 }
 
-static int mdpy_open(struct vfio_device *vdev)
-{
-	return 0;
-}
-
-static void mdpy_close(struct vfio_device *vdev)
-{
-}
-
 static ssize_t
 resolution_show(struct device *dev, struct device_attribute *attr,
 		char *buf)
@@ -717,8 +708,6 @@ static struct attribute_group *mdev_type_groups[] = {
 };
 
 static const struct vfio_device_ops mdpy_dev_ops = {
-	.open = mdpy_open,
-	.release = mdpy_close,
 	.read = mdpy_read,
 	.write = mdpy_write,
 	.ioctl = mdpy_ioctl,

samples/vfio-mdev/mtty.c

@@ -1207,17 +1207,6 @@ static long mtty_ioctl(struct vfio_device *vdev, unsigned int cmd,
 	return -ENOTTY;
 }
 
-static int mtty_open(struct vfio_device *vdev)
-{
-	pr_info("%s\n", __func__);
-	return 0;
-}
-
-static void mtty_close(struct vfio_device *mdev)
-{
-	pr_info("%s\n", __func__);
-}
-
 static ssize_t
 sample_mtty_dev_show(struct device *dev, struct device_attribute *attr,
 		     char *buf)
@@ -1325,8 +1314,6 @@ static struct attribute_group *mdev_type_groups[] = {
 
 static const struct vfio_device_ops mtty_dev_ops = {
 	.name = "vfio-mtty",
-	.open = mtty_open,
-	.release = mtty_close,
 	.read = mtty_read,
 	.write = mtty_write,
 	.ioctl = mtty_ioctl,