drm/vmwgfx: Fix possible null pointer derefence with invalid contexts
JIRA: https://issues.redhat.com/browse/RHEL-3181
CVE: CVE-2022-38096
Signed-off-by: Jocelyn Falempe jfalempe@redhat.com
JIRA: https://issues.redhat.com/browse/RHEL-3181
CVE: CVE-2022-38096
Signed-off-by: Jocelyn Falempe jfalempe@redhat.com