greybus: operation: add missing gb_operation_response_send() export

Export gb_operation_response_send() for other modules
Signed-off-by: Matt Porter <mporter@linaro.org>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

drivers/staging/greybus/operation.c

@@ -734,6 +734,7 @@ int gb_operation_response_send(struct gb_operation *operation, int errno)
 
 	return gb_message_send(operation->response);
 }
+EXPORT_SYMBOL_GPL(gb_operation_response_send);
 
 /*
  * This function is called when a buffer send request has completed.