Backport of "d3d11window_win32: fix crash on RC unprepare() vs window_proc()" into 1.22
requested to merge tpm/gstreamer:mr-6187-backport-into-1.22-d3d11window_win32_fix_rc_on_message_when_stopping into 1.22
Backport of !6187 (merged) "d3d11window_win32: fix crash on RC unprepare() vs window_proc()".
Commits:
- f92c27a4 d3d11window_win32: fix crash on RC unprepare() vs window_proc()