Backport of "msdk: check GstMsdkContext instead of mfxSession instance" into 1.18
Backport of !1867 (merged) "msdk: check GstMsdkContext instead of mfxSession instance".
Commits:
- 86fdd391 msdk: check GstMsdkContext instead of mfxSession instance
Backport of !1867 (merged) "msdk: check GstMsdkContext instead of mfxSession instance".
Commits: