Fix typo

Author: jmikola

src/libmongoc/tests/unified/result.c

@@ -152,7 +152,7 @@ result_from_bulk_write (result_t *result, bson_t *reply, bson_error_t *error)
             write_result, "upsertedIds", rewritten_upserted_ids);
       } else {
          /* upsertedIds is a required field in BulkWriteResult, so append an
-          * empty document even if not documents were upserted. */
+          * empty document even if no documents were upserted. */
          upserted_ids = bson_new ();
          BSON_APPEND_DOCUMENT (write_result, "upsertedIds", upserted_ids);
       }