multicast/discovery: Avoid leaking the context in tests (govet)

Signed-off-by: Julian Pelizäus <[email protected]>

multicast/discovery_test.go

@@ -103,8 +103,9 @@ func (m *multicastSuite) Test_Lookup() {
 		testDiscovery := NewDiscovery(c.lookupIface, c.lookupPort)
 
 		ctx := context.Background()
+		var cancel context.CancelFunc
 		if c.lookupTimeout > 0 {
-			ctx, _ = context.WithTimeoutCause(ctx, c.lookupTimeout, fmt.Errorf("Timeout exceeded"))
+			ctx, cancel = context.WithTimeoutCause(ctx, c.lookupTimeout, fmt.Errorf("Timeout exceeded"))
 		}
 
 		receivedInfo, err := testDiscovery.Lookup(ctx, c.lookupVersion)
@@ -116,6 +117,11 @@ func (m *multicastSuite) Test_Lookup() {
 			m.Require().Equal(c.lookupErr.Error(), err.Error())
 		}
 
+		// Cancel the timeout to avoid leaking the context.
+		if cancel != nil {
+			cancel()
+		}
+
 		// Stop the responder.
 		err = discovery.StopResponder()
 		m.Require().NoError(err)