[THCTensorMath] Remove use of broken THInf macro, which caused UB
[THCTensorMath] Remove use of broken THInf macro, which caused UB

luketwitter/cutorch,torch/cutorch,torch/cutorch,luketwitter/cutorch,wickedfoo/cutorch,torch/cutorch,yvan-sraka/cutorch,yvan-sraka/cutorch,wickedfoo/cutorch