va: fix memory error when elements from different GPU devices connect in one pipeline.
The pipeline such as:
gst-launch-1.0 -vf filesrc location=test.264 ! h264parse ! vah264dec ! queue ! varenderD129postproc ! fakesink
may cause pipeline error and even GPU hang for multi device environment.
We should report the correct error and at least avoid GPU hang.
Fixes: #1167 (closed)
Edited by Seungha Yang