test: v4l2_device: release capture device resources

Ensure that the cleanup operation releases the device and resources.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

test/v4l2_device/v4l2_device_test.cpp

@@ -63,5 +63,9 @@ void V4L2DeviceTest::cleanup()
 {
 	media_->release();
 
+	capture_->streamOff();
+	capture_->releaseBuffers();
+	capture_->close();
+
 	delete capture_;
 };