Fix incorrect documentation comment (has many -> has one) (go-gorm#6382)

Author: johannes-riecken

utils/tests/models.go

@@ -11,7 +11,7 @@ import (
 // He works in a Company (belongs to), he has a Manager (belongs to - single-table), and also managed a Team (has many - single-table)
 // He speaks many languages (many to many) and has many friends (many to many - single-table)
 // His pet also has one Toy (has one - polymorphic)
-// NamedPet is a reference to a Named `Pets` (has many)
+// NamedPet is a reference to a named `Pet` (has one)
 type User struct {
 	gorm.Model
 	Name      string