fix: Remove a newline from logging statement in changeSpotPrice calculation

[mvadari]

High Level Overview of Change

Removed unnecessary newline in logging statement.

std::endl is unneeded in JLOG, since it automatically places a newline at the end of the string. So it's an unnecessary flush.

Context of Change

AI review triage

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 79.8%. Comparing base (0446bef) to head (1b081e4).
⚠️ Report is 48 commits behind head on develop.

Additional details and impacted files

@@            Coverage Diff            @@
##           develop   #6547     +/-   ##
=========================================
- Coverage     79.8%   79.8%   -0.0%     
=========================================
  Files          878     878             
  Lines        67887   67887             
  Branches      7549    7551      +2     
=========================================
- Hits         54206   54204      -2     
- Misses       13681   13683      +2     

Files with missing lines	Coverage Δ
include/xrpl/tx/transactors/dex/AMMHelpers.h	96.0% <100.0%> (ø)
src/libxrpl/tx/transactors/dex/AMMDeposit.cpp	96.4% <ø> (ø)

... and 2 files with indirect coverage changes

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