asfdemux: don't leak payload if we are not pushing it
asfdemux: don't leak payload if we are not pushing it

fluendo/gst-plugins-ugly,fluendo/gst-plugins-ugly,freedesktop-unofficial-mirror/gstreamer-sdk__gst-plugins-ugly,freedesktop-unofficial-mirror/gstreamer-sdk__gst-plugins-ugly,freedesktop-unofficial-mirror/gstreamer-sdk__gst-plugins-ugly,fluendo/gst-plugins-ugly