drm/virtio: fix NULL pointer dereference in virtiogpuconngetmodes
This is an automated ID intended to aid in discovery of potential security vulnerabilities. The actual impact and attack plausibility have not yet been proven. This ID is fixed in Linux Kernel version v5.15.46 by commit 32e10aabc287f09a148ff759bb9ce70b01b0012c. For more details please see the references link.