corrected callback to handle cancelled requests

src/mona.c

@@ -452,7 +452,8 @@ static int mona_callback(const struct na_cb_info *info)
 {
     na_return_t na_ret = info->ret;
     mona_request_t req = (mona_request_t)(info->arg);
-    if(info->type == NA_CB_RECV_UNEXPECTED) {
+
+    if(na_ret == NA_SUCCESS && info->type == NA_CB_RECV_UNEXPECTED) {
         na_addr_t source = info->info.recv_unexpected.source;
         na_tag_t tag     = info->info.recv_unexpected.tag;
         na_size_t size   = info->info.recv_unexpected.actual_buf_size;
@@ -466,6 +467,7 @@ static int mona_callback(const struct na_cb_info *info)
             *(req->size) = size;
         }
     }
+
     ABT_eventual_set(req->eventual, &na_ret, sizeof(na_ret));
     return NA_SUCCESS;
 }