add golangci-lint linter (#5499)

plugin/transfer/failed_write_test.go

@@ -12,10 +12,9 @@ import (
 
 type badwriter struct {
 	dns.ResponseWriter
-	count int
 }
 
-func (w *badwriter) WriteMsg(res *dns.Msg) error { return fmt.Errorf("failed to write msg") }
+func (w *badwriter) WriteMsg(_ *dns.Msg) error { return fmt.Errorf("failed to write msg") }
 
 func TestWriteMessageFailed(t *testing.T) {
 	transfer := newTestTransfer()

plugin/transfer/setup_test.go

@@ -98,7 +98,6 @@ func TestParse(t *testing.T) {
 			for k, zone := range x.Zones {
 				if tc.exp.xfrs[j].Zones[k] != zone {
 					t.Errorf("Test %d expected zone %v, got %v", i, tc.exp.xfrs[j].Zones[k], zone)
-
 				}
 			}
 			// Check to
@@ -108,7 +107,6 @@ func TestParse(t *testing.T) {
 			for k, to := range x.to {
 				if tc.exp.xfrs[j].to[k] != to {
 					t.Errorf("Test %d expected %v in 'to', got %v", i, tc.exp.xfrs[j].to[k], to)
-
 				}
 			}
 		}

plugin/transfer/transfer.go

@@ -167,7 +167,6 @@ func (t *Transfer) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Ms
 			return dns.RcodeServerFailure, err
 		}
 		l += len(rrs)
-
 	}
 
 	close(ch)     // Even though we close the channel here, we still have