gpu/headless: plug resource leaks in tests

Signed-off-by: Elias Naur <mail@eliasnaur.com>

gpu/headless/driver_test.go

@@ -212,6 +212,7 @@ func newDriver(t *testing.T) driver.Device {
 	b.BeginFrame(nil, true, image.Pt(1, 1))
 	t.Cleanup(func() {
 		b.EndFrame()
+		b.Release()
 		ctx.ReleaseCurrent()
 		runtime.UnlockOSThread()
 		ctx.Release()

gpu/headless/headless.go

@@ -66,6 +66,7 @@ func NewWindow(width, height int) (*Window, error) {
 		if err != nil {
 			fbo.Release()
 			fboTex.Release()
+			dev.Release()
 			return err
 		}
 		w.fboTex = fboTex
@@ -96,6 +97,10 @@ func (w *Window) Release() {
 			w.gpu.Release()
 			w.gpu = nil
 		}
+		if w.dev != nil {
+			w.dev.Release()
+			w.dev = nil
+		}
 		return nil
 	})
 	if w.ctx != nil {