vmbus: constify parameters where possible

Functions that just query state of ring buffer can have parameters
marked const.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 08eb71a..62bbf3c 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -138,8 +138,8 @@
  * for the specified ring buffer
  */
 static inline void
-hv_get_ringbuffer_availbytes(struct hv_ring_buffer_info *rbi,
-			  u32 *read, u32 *write)
+hv_get_ringbuffer_availbytes(const struct hv_ring_buffer_info *rbi,
+			     u32 *read, u32 *write)
 {
 	u32 read_loc, write_loc, dsize;
 
@@ -153,7 +153,7 @@
 	*read = dsize - *write;
 }
 
-static inline u32 hv_get_bytes_to_read(struct hv_ring_buffer_info *rbi)
+static inline u32 hv_get_bytes_to_read(const struct hv_ring_buffer_info *rbi)
 {
 	u32 read_loc, write_loc, dsize, read;
 
@@ -167,7 +167,7 @@
 	return read;
 }
 
-static inline u32 hv_get_bytes_to_write(struct hv_ring_buffer_info *rbi)
+static inline u32 hv_get_bytes_to_write(const struct hv_ring_buffer_info *rbi)
 {
 	u32 read_loc, write_loc, dsize, write;
 
@@ -1448,9 +1448,9 @@
 
 /* Get the start of the ring buffer. */
 static inline void *
-hv_get_ring_buffer(struct hv_ring_buffer_info *ring_info)
+hv_get_ring_buffer(const struct hv_ring_buffer_info *ring_info)
 {
-	return (void *)ring_info->ring_buffer->buffer;
+	return ring_info->ring_buffer->buffer;
 }
 
 /*