hlssink,hlssink2: Ensure writing ENDLIST tag at the end

hlssink,hlssink2: Ensure writing ENDLIST tag at the end

hlssink* elements could be finalized without EOS event, and in that case
the final playlist might not include the EXT-X-ENDLIST tag.
Since missing ENDLIST tag means it's live stream, but we did't intend it,
hlssink* elements should put the tag at the end.