libsel4allocman: use correct word size
diff --git a/libsel4allocman/src/cspace/two_level.c b/libsel4allocman/src/cspace/two_level.c
index e60856a..9420fdf 100644
--- a/libsel4allocman/src/cspace/two_level.c
+++ b/libsel4allocman/src/cspace/two_level.c
@@ -215,8 +215,8 @@
     cspacepath_t path;
     cspace_single_level_destroy(alloc, &cspace->second_levels[index]->second_level);
     if (cspace->second_levels[index]->cookie_valid) {
-        int error UNUSED;
-        error = seL4_CNode_Delete(cspace->config.cnode, index, 32 - cspace->config.level_two_bits);
+        int error = seL4_CNode_Delete(cspace->config.cnode, index,
+                                      seL4_WordBits - cspace->config.level_two_bits);
         assert(error == seL4_NoError);
         allocman_utspace_free(alloc, cspace->second_levels[index]->cookie, cspace->config.level_two_bits + seL4_SlotBits);
     }