changing the destruct function of list release API to release list items

caused a bug in oshmem application. Fixing the bug with this patch

oshmem/mca/memheap/base/memheap_base_mkey.c

@@ -482,6 +482,11 @@ void memheap_oob_destruct(void)
         MPI_Request_free(&r->recv_req);
     }
 
+    /*clear these list object as they don't belong here */
+    while (NULL != opal_list_remove_first(&memheap_oob.req_list)) {
+        continue;
+    }
+
     OBJ_DESTRUCT(&memheap_oob.req_list);
     OBJ_DESTRUCT(&memheap_oob.lck);
     OBJ_DESTRUCT(&memheap_oob.cond);