fix reshape error when multi GPU bachsize > 1 not packed

[Ultized]

fix reshape error when multi GPU bachsize > 1 and not packed.

when bachsize =2 , GPU size = 2
(world_view,) = all_to_all_tensor_list(
world_size,
[(torch.ones_like(radii) * torch.arange(0, 4, device = radii.device)[:, None] + torch.ones_like(radii) * world_rank * radii.shape[0]).flatten(0, 1)],
splits=[C_i * N for C_i in C_world],
output_splits=[C * N_i for N_i in N_world],
)
world_view2 = world_view.reshape(C, -1)

when world_rank = 1 the world_view2 is
tensor([[2, 2, 2, ..., 3, 3, 3],
[6, 6, 6, ..., 7, 7, 7]], device='cuda:1')
It should tensor([[2, 2, 2, ..., 6, 6, 6],
[3, 3, 3, ..., 7, 7, 7]], device='cuda:1')

[liruilong940607]

Thanks for the fix!

Mind run the black format?

black==22.3.0
black . gsplat/ tests/ examples/ profiling/ --check

[liruilong940607]

LGTM!