list_masking_views func efficiency optimization

[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 #497 (06779c3) into eternus-mapping (419ecc3) will decrease coverage by 0.00%.
The diff coverage is 90.90%.

@@                 Coverage Diff                 @@
##           eternus-mapping     #497      +/-   ##
===================================================
- Coverage            71.05%   71.05%   -0.01%     
===================================================
  Files                  180      180              
  Lines                19091    19090       -1     
  Branches              2843     2842       -1     
===================================================
- Hits                 13566    13564       -2     
  Misses                4660     4660              
- Partials               865      866       +1     

Impacted Files	Coverage Δ
delfin/drivers/fujitsu/eternus/eternus_stor.py	88.18% <88.88%> (-0.22%)	⬇️
delfin/drivers/fujitsu/eternus/consts.py	100.00% <100.00%> (ø)
delfin/drivers/fake_storage/__init__.py	94.40% <0.00%> (ø)