Reduce tensor size for topk test
Reduce tensor size for topk test

This particular test (top-k) can be rather slow - I suggest reducing the used tensor sizes to avoid test durations of 10+ minutes.
yvan-sraka/cutorch,luketwitter/cutorch,torch/cutorch,torch/cutorch,yvan-sraka/cutorch,luketwitter/cutorch,torch/cutorch,wickedfoo/cutorch,wickedfoo/cutorch