Loop optimization: move maxlen check outside to reduce unnecessary checks

[hengyoush]

A trival pr, move maxlen check outside to reduce unnecessary ecks

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 2 lines in your changes missing coverage. Please review.

Project coverage is 70.94%. Comparing base (dc9ca1b) to head (b6ee3f3).
Report is 7 commits behind head on unstable.

Files with missing lines	Patch %	Lines
src/hashtable.c	0.00%	2 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##           unstable    #1557      +/-   ##
============================================
- Coverage     70.98%   70.94%   -0.04%     
============================================
  Files           120      120              
  Lines         65061    65061              
============================================
- Hits          46185    46159      -26     
- Misses        18876    18902      +26     

Files with missing lines	Coverage Δ
src/hashtable.c	77.27% <0.00%> (-0.09%)	⬇️

... and 21 files with indirect coverage changes