rust: fix lint warnings about mixed case hex literals

[AkakiAlice]

Ticket: #4593

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• I have read the contributing guide lines at https://redmine.openinfosecfoundation.org/projects/suricata/wiki/Contributing
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• I have updated the user guide (in doc/userguide/) to reflect the changes made (if applicable)

Link to redmine ticket: https://redmine.openinfosecfoundation.org/issues/4593

Previous PR: #8003

Describe changes:

• Update commit message

[inashivb]

Nice job, @AkakiAlice ! LGTM. :)

[codecov]

Codecov Report

Merging #8005 (ffb16d9) into master (2158dbf) will decrease coverage by 0.02%.
The diff coverage is 0.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #8005      +/-   ##
==========================================
- Coverage   81.65%   81.62%   -0.03%     
==========================================
  Files         953      953              
  Lines      275749   275749              
==========================================
- Hits       225158   225082      -76     
- Misses      50591    50667      +76     

Flag	Coverage Δ
fuzzcorpus	63.69% <0.00%> (+0.31%)	⬆️
suricata-verify	58.89% <0.00%> (-0.04%)	⬇️
unittests	63.47% <0.00%> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

[jasonish]

Merged via #8051, Thanks!