destroy window in finalize function.
destroy window in finalize function.

when playing different streams, it will re-init plugin objects.
since we create a window during init, we need to destroy it when finalize.

Signed-off-by: Haifeng Yan <cffc31285a33ae3420150af7df689b699905f42b@gmail.com>

hisilicon/gst-hivosink,commshare/gst-hivosink,commshare/gst-hivosink,hisilicon/gst-hivosink