MSDK does not create internal acceleration device on Linux,
So MFXVideoCORE_SetHandle() is necessary.
It has been added for ff_qsv_init_session_device().
But missed for ff_qsv_init_internal_session() due to commit
1f26a231 overwrited commit db89f455

Fix #7030
Signed-off-by: Zhong Li <zhong.li@intel.com>