Issue fix 7648: avoid snapshot leak on expose failure

[Lyndon-Li]

Fix issue #7648. Adjust the exposing logic to avoid exposing failure and snapshot leak when expose fails

[codecov]

Codecov Report

Attention: Patch coverage is 94.11765% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 61.76%. Comparing base (f25c154) to head (dcf760d).
Report is 2 commits behind head on main.

Files	Patch %	Lines
pkg/exposer/csi_snapshot.go	94.11%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7662      +/-   ##
==========================================
+ Coverage   61.26%   61.76%   +0.49%     
==========================================
  Files         276      276              
  Lines       31338    24716    -6622     
==========================================
- Hits        19200    15265    -3935     
+ Misses      10784     8098    -2686     
+ Partials     1354     1353       -1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.