Backport of "ksvideo, directshow: Fix reference leaks in device providers" into 1.22
requested to merge tpm/gstreamer:backport-mr-4224-into-1.22-directshow_winks_device_provider_leak_fix into 1.22
Backport of !4224 (merged) "Fix reference leaks in gst_ks_device_provider_start and gst_dshow_device_provider_start".
Commits: