Remove hostmapping redundant code

[joseph-v]

What this PR does / why we need it: Remove hostmapping redundant code

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[bot]]

Codecov Report

Merging #796 (fdc639b) into master (6774a9a) will increase coverage by 0.09%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #796      +/-   ##
==========================================
+ Coverage   70.54%   70.63%   +0.09%     
==========================================
  Files         180      180              
  Lines       18638    18551      -87     
  Branches     2749     2719      -30     
==========================================
- Hits        13148    13104      -44     
+ Misses       4646     4604      -42     
+ Partials      844      843       -1     

Impacted Files	Coverage Δ
delfin/task_manager/tasks/resources.py	94.13% <100.00%> (+8.29%)	:arrow_up:
delfin/drivers/fake_storage/__init__.py	93.89% <0.00%> (+0.25%)	:arrow_up: