packet: Remove trailing whitespace

[jlduran]

Checklist:

• If you are new to Scapy: I have checked CONTRIBUTING.md (esp. section submitting-pull-requests)
• I squashed commits belonging together
• I added unit tests or explained why they are not relevant
• I executed the regression tests (using cd test && ./run_tests or tox)
• If the PR is still not finished, please create a Draft Pull Request

[codecov]

Codecov Report

Merging #4163 (eb0d223) into master (363d376) will decrease coverage by 0.01%.
Report is 1 commits behind head on master.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #4163      +/-   ##
==========================================
- Coverage   81.78%   81.77%   -0.01%     
==========================================
  Files         330      330              
  Lines       76340    76340              
==========================================
- Hits        62434    62430       -4     
- Misses      13906    13910       +4     

Files	Coverage Δ
scapy/packet.py	83.67% <100.00%> (ø)

... and 5 files with indirect coverage changes

[gpotter2]

Thanks for the PR !