Correct the way update is rendered

Author: perrito666

db/chain/chain.go

@@ -594,9 +594,8 @@ func (ec *ExpresionChain) render(raw bool) (string, []interface{}, error) {
 		if len(expresion) == 0 {
 			return "", nil, errors.Errorf("empty update expresion")
 		}
-		query = fmt.Sprintf("UPDATE ? SET (%s)",
-			ec.mainOperation.expresion)
-		args = append(args, ec.table)
+		query = fmt.Sprintf("UPDATE %s SET (%s)",
+			ec.table, ec.mainOperation.expresion)
 		args = append(args, ec.mainOperation.arguments...)
 	// SELECT, DELETE
 	case sqlSelect, sqlDelete: