drm/nouveau/kms/nv50-: fix case where notifier buffer is at offset 0

[ Upstream commit caeb6ab899c3d36a74cda6e299c6e1c9c4e2a22e ]

VRAM offset 0 is a valid address, triggered on GA102.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
3 files changed