fix: 'type XXXX int' will print wrong sql to terminal

[wangzeping722]

• Do only one thing
• Non breaking API changes
• Tested

What did this pull request do?

ref: #6898

The wrong sql printed to the terminal can be confusing when use type XXX int, so fix it.

User Case Description

type UserStatus int

const (
	Normal UserStatus = 1
	Forbid UserStatus = 2
)

DB.Where("status = ?", Normal).Find(&users)

It print:

SELECT * FROM `users` WHERE status = '1' AND `users`.`deleted_at` IS NULL

The expected print is:

SELECT * FROM `users` WHERE status = 1 AND `users`.`deleted_at` IS NULL

[jinzhu]

thank you for your PR