mesh: Fix cdb key update iteration
Fixes copy/paste error taking the size of the the wrong array.
this is port of
@@ -2432,7 +2432,7 @@ static struct key_update *cdb_key_update_find(bool app_key, u16_t key_idx,
match = NULL;
*free_slot = NULL;
- for (i = 0; i < ARRAY_SIZE(key_updates); i++) {
+ for (i = 0; i < ARRAY_SIZE(cdb_key_updates); i++) {
struct key_update *update = &cdb_key_updates[i];
if (!update->valid) {
