Fix Windows build.

Windows doesn't like returning void values from void functions.

Change-Id: I9fbcb26098a5434ff4e8980f3ed0cd7b2567d658
diff --git a/decrepit/obj/obj_decrepit.c b/decrepit/obj/obj_decrepit.c
index a03ea0f..06051f1 100644
--- a/decrepit/obj/obj_decrepit.c
+++ b/decrepit/obj/obj_decrepit.c
@@ -67,5 +67,5 @@
 
 void OBJ_NAME_do_all(int type, void (*callback)(const OBJ_NAME *, void *arg),
                      void *arg) {
-  return OBJ_NAME_do_all_sorted(type, callback, arg);
+  OBJ_NAME_do_all_sorted(type, callback, arg);
 }