False positives with custom errors-package and errors.New(fmt.Sprintf(...

[kristofferingemansson]

When using a custom errors-package implementing New(...) in conjunction with fmt.Sprintf(...) golint incorrectly suggests usage of fmt.Errorf(...) instead.
A custom errors-package will most likely return an error of different type than "errorString" of the core errors-package and hence fmt.Errorf(...) will not be equivalent.

Sample code:

import (
	"fmt"
	"github.com/pkg/errors"
)

func main() {
	errors.New(fmt.Sprintf("%v", 10))
}

Output:

main.go:9:2: should replace errors.New(fmt.Sprintf(...)) with fmt.Errorf(...)
Found 1 lint suggestions; failing.

Expected:
No warnings