lib: make table_compute_checksum() arguments const

table_compute_checksum() does neither changes the content of the
checksummed buffer nor the buffer length. Adding const to the
definition makes the function wider usable.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

include/tables_csum.h

@@ -17,6 +17,6 @@
  * @len:	configuration table size
  * @return:	the 8-bit checksum
  */
-u8 table_compute_checksum(void *v, int len);
+u8 table_compute_checksum(const void *v, const int len);
 
 #endif

lib/tables_csum.c

@@ -5,9 +5,9 @@
 
 #include <linux/types.h>
 
-u8 table_compute_checksum(void *v, int len)
+u8 table_compute_checksum(const void *v, const int len)
 {
-	u8 *bytes = v;
+	const u8 *bytes = v;
 	u8 checksum = 0;
 	int i;