Fix kernel-doc warnings in dma-ring.c:

dma-ring.c:130: warning: No description found for return value of 'mei_dma_copy_from'
dma-ring.c:150: warning: No description found for return value of 'mei_dma_copy_to'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Tomas Winkler <tomas.winkler@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/misc/mei/dma-ring.c |    4 ++++
 1 file changed, 4 insertions(+)

diff -- a/drivers/misc/mei/dma-ring.c b/drivers/misc/mei/dma-ring.c
--- a/drivers/misc/mei/dma-ring.c
+++ b/drivers/misc/mei/dma-ring.c
@@ -124,6 +124,8 @@ void mei_dma_ring_reset(struct mei_devic
  * @buf: data buffer
  * @offset: offset in slots.
  * @n: number of slots to copy.
+ *
+ * Return: number of bytes copied
  */
 static size_t mei_dma_copy_from(struct mei_device *dev, unsigned char *buf,
 				u32 offset, u32 n)
@@ -144,6 +146,8 @@ static size_t mei_dma_copy_from(struct m
  * @buf: data buffer
  * @offset: offset in slots.
  * @n: number of slots to copy.
+ *
+ * Return: number of bytes copied
  */
 static size_t mei_dma_copy_to(struct mei_device *dev, unsigned char *buf,
 			      u32 offset, u32 n)