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

entc/gen/template/ent.tmpl

@@ -111,11 +111,11 @@ func ({{ $receiver }} *{{ $.Name }}) Update() *{{ $.UpdateOneName }} {
 // Unwrap unwraps the {{ $.Name }} entity that was returned from a transaction after it was closed,
 // so that all future queries will be executed through the driver which created the transaction.
 func ({{ $receiver }} *{{ $.Name }}) Unwrap() *{{ $.Name }} {
-	tx, ok := {{ $receiver }}.config.driver.(*txDriver)
+	_tx, ok := {{ $receiver }}.config.driver.(*txDriver)
 	if !ok {
 		panic("{{ $pkg }}: {{ $.Name }} is not a transactional entity")
 	}
-	{{ $receiver }}.config.driver = tx.drv
+	{{ $receiver }}.config.driver = _tx.drv
 	return {{ $receiver }}
 }
 
@@ -243,4 +243,4 @@ func ({{ $receiver }} {{ $slice }}) config(cfg config) {
 			{{- xtemplate $tmpl $ }}
 		{{- end }}
 	{{- end }}
-{{ end }}
+{{ end }}