virtio: fix typo in comment

- Delete "@request_vqs" and "@free_vqs" comments, since
  they are no longer in struct virtio_config_ops.
- According to the macro below, "@val" should be "@v".
Signed-off-by: NChen Baozi <chenbaozi@gmail.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

include/linux/virtio_config.h

@@ -74,15 +74,6 @@
  * @set_status: write the status byte
  *	vdev: the virtio_device
  *	status: the new status byte
- * @request_vqs: request the specified number of virtqueues
- *	vdev: the virtio_device
- *	max_vqs: the max number of virtqueues we want
- *      If supplied, must call before any virtqueues are instantiated.
- *      To modify the max number of virtqueues after request_vqs has been
- *      called, call free_vqs and then request_vqs with a new value.
- * @free_vqs: cleanup resources allocated by request_vqs
- *	vdev: the virtio_device
- *      If supplied, must call after all virtqueues have been deleted.
  * @reset: reset the device
  *	vdev: the virtio device
  *	After this, status and feature negotiation must be done again
@@ -156,7 +147,7 @@ static inline bool virtio_has_feature(const struct virtio_device *vdev,
  * @vdev: the virtio device
  * @fbit: the feature bit
  * @offset: the type to search for.
- * @val: a pointer to the value to fill in.
+ * @v: a pointer to the value to fill in.
  *
  * The return value is -ENOENT if the feature doesn't exist.  Otherwise
  * the config value is copied into whatever is pointed to by v. */