pkg/cri: remove useless code

[fuweid]

Signed-off-by: Wei Fu fuweid89@gmail.com

Ⅰ. Describe what this PR did

For the user, we aleady uses the functions provided by runc vendor.
Therefore we remove it.

Ⅱ. Does this pull request fix one issue?

none

Ⅲ. Why don't you add test cases (unit test/integration test)? (你真的觉得不需要加测试吗？)

no need

Ⅳ. Describe how to verify it

CI

Ⅴ. Special notes for reviews

[codecov]

Codecov Report

Merging #2721 into master will increase coverage by 0.42%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2721      +/-   ##
==========================================
+ Coverage   69.26%   69.68%   +0.42%     
==========================================
  Files         278      277       -1     
  Lines       17486    17370     -116     
==========================================
- Hits        12111    12104       -7     
+ Misses       4035     3924     -111     
- Partials     1340     1342       +2

Flag	Coverage Δ
#criv1alpha2_test	39.88% <ø> (+0.34%)	⬆️
#integration_test_0	36.56% <ø> (+0.19%)	⬆️
#integration_test_1	35.48% <ø> (+0.23%)	⬆️
#integration_test_2	36.87% <ø> (+0.2%)	⬆️
#integration_test_3	35.34% <ø> (+0.32%)	⬆️
#node_e2e_test	35.18% <ø> (+0.06%)	⬆️
#unittest	27.54% <ø> (+0.19%)	⬆️

Impacted Files	Coverage Δ
cri/stream/httpstream/spdy/connection.go	65.9% <ø> (+7.9%)	⬆️
pkg/user/user.go	64.86% <ø> (+24.86%)	⬆️
cri/ocicni/cni_manager.go	58.82% <0%> (-11.77%)	⬇️
daemon/mgr/spec_linux.go	78.92% <0%> (-1.08%)	⬇️
cri/v1alpha2/cri.go	71.53% <0%> (-0.65%)	⬇️
ctrd/client.go	65.73% <0%> (+1.68%)	⬆️
pkg/streams/utils.go	91.66% <0%> (+2.38%)	⬆️
daemon/mgr/events.go	91.78% <0%> (+2.73%)	⬆️

[Ace-Tang]

for user code, lgtm, since we use runc package to reslove , for exec code, maybe @rudyfly need to check?

[zhuangqh]

LGTM actually dead code

[rudyfly]

LGTM