Fix compile error caused by entc template when Entity name has initials TX

[hax10]

When creating an Entity with initials "TX", e.g. TumorXrays,

the code generated by entc cannot compile, because of a name clash in the generated transaction (tx) Unwrap() function:

func (tx *TumorXrays) Unwrap() *TumorXrays {
	tx, ok := tx.config.driver.(*txDriver)
	...

[a8m]

Thanks for the contribution @hax10 🙏

[a8m]

@all-contributors please add @hax10 for code

[allcontributors]

@a8m

I've put up a pull request to add @hax10! 🎉