v4l2object: plug memory-leak
v4l2object: plug memory-leak

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-good/-/merge_requests/718>

GStreamer/gst-plugins-good,GStreamer/gst-plugins-good,GStreamer/gst-plugins-good,GStreamer/gst-plugins-good