Logical operator style fix in reduce.cuh

[isVoid]

Addressing #10447 (comment), logical operators should be consistent in a statement.

[jrhemstad]

I don't have any qualms with mixing && and not. I almost always use not instead of ! because ! is too easy to overlook when reading a statement.

[codecov]

Codecov Report

Merging #10670 (cadd38b) into branch-22.06 (3c13ef1) will increase coverage by 0.03%.
The diff coverage is 90.51%.

❗ Current head cadd38b differs from pull request most recent head f2c91d1. Consider uploading reports for the commit f2c91d1 to get more accurate results

@@               Coverage Diff                @@
##           branch-22.06   #10670      +/-   ##
================================================
+ Coverage         86.33%   86.37%   +0.03%     
================================================
  Files               140      142       +2     
  Lines             22289    22356      +67     
================================================
+ Hits              19244    19309      +65     
- Misses             3045     3047       +2     

Impacted Files	Coverage Δ
python/cudf/cudf/core/_base_index.py	85.45% <ø> (ø)
python/cudf/cudf/core/algorithms.py	90.47% <ø> (ø)
python/cudf/cudf/core/cut.py	82.69% <ø> (ø)
python/cudf/cudf/core/groupby/groupby.py	91.72% <ø> (+0.22%)	⬆️
python/cudf/cudf/core/indexed_frame.py	91.77% <ø> (ø)
python/cudf/cudf/core/multiindex.py	92.14% <ø> (ø)
python/cudf/cudf/core/series.py	95.28% <ø> (ø)
python/cudf/cudf/core/tools/numeric.py	89.24% <ø> (ø)
python/cudf/cudf/utils/cudautils.py	59.83% <ø> (ø)
python/cudf/cudf/utils/ioutils.py	79.60% <ø> (ø)
... and 16 more

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[bdice]

I feel similarly to @jrhemstad on this — I would rather change && to and than not to ! if we had a consensus that we like consistency in logical operator forms. The full words also make the statement easier to read (à la Python). However I don’t think we need to do anything here and I’d vote to close this.

[isVoid]

That's ok with me. It irritates me a little bit when I see inconsistencies in the same file with ! and not such as here: https://github.com/rapidsai/cudf/pull/10447/files#r851226348. But since we are still don't have a consensus to this I'm ok to close this.