pure codeview-Remove unnecessary function wrapping

[zhilong-xu]

What this PR does / why we need it:

Which issue this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged): fixes #

Special notes for your reviewer:

Release note:

[codecov]

Codecov Report

Merging #300 (555bdc8) into pure (19a7a81) will decrease coverage by 0.06%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             pure     #300      +/-   ##
==========================================
- Coverage   70.65%   70.59%   -0.07%     
==========================================
  Files         166      166              
  Lines       16120    16090      -30     
  Branches     1985     1985              
==========================================
- Hits        11390    11359      -31     
  Misses       4055     4055              
- Partials      675      676       +1     

Impacted Files	Coverage Δ
delfin/drivers/pure/pure/rest_handler.py	33.72% <ø> (-17.15%)	⬇️
delfin/drivers/pure/pure/pure_storage.py	89.06% <100.00%> (ø)
delfin/drivers/fake_storage/__init__.py	95.34% <0.00%> (-0.28%)	⬇️