vringh: fix typos in the vringh_init_* documentation

Replace `userpace` with `userspace`.

Cc: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Message-Id: <20230331080208.17002-1-sgarzare@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>

drivers/vhost/vringh.c

@@ -636,9 +636,9 @@ static inline int xfer_to_user(const struct vringh *vrh,
  * @features: the feature bits for this ring.
  * @num: the number of elements.
  * @weak_barriers: true if we only need memory barriers, not I/O.
- * @desc: the userpace descriptor pointer.
- * @avail: the userpace avail pointer.
- * @used: the userpace used pointer.
+ * @desc: the userspace descriptor pointer.
+ * @avail: the userspace avail pointer.
+ * @used: the userspace used pointer.
  *
  * Returns an error if num is invalid: you should check pointers
  * yourself!
@@ -911,9 +911,9 @@ static inline int kern_xfer(const struct vringh *vrh, void *dst,
  * @features: the feature bits for this ring.
  * @num: the number of elements.
  * @weak_barriers: true if we only need memory barriers, not I/O.
- * @desc: the userpace descriptor pointer.
- * @avail: the userpace avail pointer.
- * @used: the userpace used pointer.
+ * @desc: the userspace descriptor pointer.
+ * @avail: the userspace avail pointer.
+ * @used: the userspace used pointer.
  *
  * Returns an error if num is invalid.
  */
@@ -1306,9 +1306,9 @@ static inline int putused_iotlb(const struct vringh *vrh,
  * @features: the feature bits for this ring.
  * @num: the number of elements.
  * @weak_barriers: true if we only need memory barriers, not I/O.
- * @desc: the userpace descriptor pointer.
- * @avail: the userpace avail pointer.
- * @used: the userpace used pointer.
+ * @desc: the userspace descriptor pointer.
+ * @avail: the userspace avail pointer.
+ * @used: the userspace used pointer.
  *
  * Returns an error if num is invalid.
  */