Variable Name Clarity (#78478)
The current "output_height" and "output_width" names on lines 198 and 199 are not consistent with [lines 132 and 133 in Col2Im.h](https://github.com/pytorch/pytorch/blob/3ee863cb7c07699b94e36715a82a25744560f2d9/aten/src/ATen/native/cuda/Col2Im.cu#L126). This was confusing to me, so this PR is a quick fix. This fix is also more consistent with [lines 122 and 132 from the same file](https://github.com/pytorch/pytorch/blob/3ee863cb7c07699b94e36715a82a25744560f2d9/aten/src/ATen/native/cuda/im2col.cuh#L108).
Fixes no issue number.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/78478
Approved by: https://github.com/ngimel
