fix: issues with go report

[metayd]

Ⅰ. Describe what this PR did

fix some issues in go report, include ineffectual assignments and typos etc

Ⅱ. Does this pull request fix one issue?

fix #964

[CLAassistant]

All committers have signed the CLA.

[pouchrobot]

We found this is your first time to contribute to Pouch, @dbdd4us
👏 We really appreciate it.
Just remind that you have read the contribution guide: https://github.com/alibaba/pouch/blob/master/CONTRIBUTING.md
If you didn't, you should do that first. If done, welcome again and please enjoy hacking! 🍻

[codecov-io]

Codecov Report

Merging #1081 into master will increase coverage by 0.03%.
The diff coverage is 0%.

@@            Coverage Diff             @@
##           master    #1081      +/-   ##
==========================================
+ Coverage   16.52%   16.56%   +0.03%     
==========================================
  Files         161      161              
  Lines        8884     8899      +15     
==========================================
+ Hits         1468     1474       +6     
- Misses       7313     7320       +7     
- Partials      103      105       +2

Impacted Files	Coverage Δ
pkg/errtypes/errors.go	35.29% <ø> (ø)	⬆️
daemon/mgr/image.go	32.46% <0%> (+0.33%)	⬆️
ctrd/client.go	0% <0%> (ø)	⬆️
pkg/kernel/kernel.go	72.72% <0%> (-10.61%)	⬇️
client/client.go	28.57% <0%> (-4.77%)	⬇️
cli/command.go	0% <0%> (ø)	⬆️

[allencloud]

Could you help to check the prjquota part's code review? @rudyfly

[allencloud]

Thanks for your work. LGTM