MYSQL Trigger update on a table
I believe this is what you need:

CREATE Trigger upd_pt 
BEFORE UPDATE ON user
FOR EACH ROW 
SET NEW.point = NEW.votes + NEW.paymentAmt


This will set points before the user record is updated, so that total will be stored.

Based on code from the MySQL 5.7 Reference Manual.

NOTE: For best results, you probably also want to have this as an INSERT trigger, and may want to adjust if votes or paymentAmt can be NULL.