drm/amdgpu: check context id for context switching (v2)

check the filp is not robust, and sometimes different contexts may
have same filp value.

v2: check both filp and ctx_id

Signed-off-by: Jammy Zhou <Jammy.Zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
2 files changed