golint fix
This PR is a small golint fix:
```
coredns/plugin/test/helpers.go
Line 283: warning: redundant if ...; err != nil check, just return error instead. (golint)
```
@@ -280,10 +280,7 @@ func SortAndCheck(resp *dns.Msg, tc Case) error {
return err
}
- if err := Section(tc, Extra, resp.Extra); err != nil {
- return err
- }
- return nil
+ return Section(tc, Extra, resp.Extra)
}
// ErrorHandler returns a Handler that returns ServerFailure error when called.
