fix: avoid overflow in progress bar percentage

[qweeah]

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #1175.

Please check the following list:

• Does the affected code have corresponding tests, e.g. unit test, E2E test?
• Does this change require a documentation update?
• Does this introduce breaking changes that would require an announcement or bumping the major version?
• Do all new files have an appropriate license header?

[codecov-commenter]

Codecov Report

Merging #1178 (78e7ba5) into main (92f9c8b) will increase coverage by 0.01%.
The diff coverage is 100.00%.

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

@@            Coverage Diff             @@
##             main    #1178      +/-   ##
==========================================
+ Coverage   80.02%   80.03%   +0.01%     
==========================================
  Files          65       65              
  Lines        3560     3562       +2     
==========================================
+ Hits         2849     2851       +2     
  Misses        495      495              
  Partials      216      216              

Files	Coverage Δ
cmd/oras/internal/display/progress/status.go	95.16% <100.00%> (+0.07%)	⬆️

[shizhMSFT]

LGTM