drm/radeon/benchmark: common modes sweep ignores 640x480@32

Sweep common_modes array should start with index 0.

Signed-off-by: Chen Jie <chenj@lemote.com>
Reviewed-by: Ilija Hadzic <ihadzic@research.bell-labs.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
1 file changed