Make `GETINFO hs/client/desc/id/<identifier>` actually work (#14845).

Not in any released version of tor.

src/or/control.c

@@ -1740,7 +1740,7 @@ getinfo_helper_dir(control_connection_t *control_conn,
       return -1;
     }
 
-    if (rend_cache_lookup_entry(question, -1, &e) > 0) {
+    if (!rend_cache_lookup_entry(question, -1, &e)) {
       /* Descriptor found in cache */
       *answer = tor_strdup(e->desc);
     } else {