bugfix: print error info twice when cmd unknown

[starnop]

Signed-off-by: Starnop starnop@163.com

Ⅰ. Describe what this PR did

pouchContainer will print error info twice when command was unknown.

Ⅱ. Does this pull request fix one issue?

fixes #1529

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 needed.

Ⅳ. Describe how to verify it

# pouch foo
Error: unknown command "foo" for "pouch"

Did you mean this?
	top

Run 'pouch --help' for usage.

Ⅴ. Special notes for reviews

Cobra will print automatic suggestions when "unknown command" errors happen.

[codecov]

Codecov Report

Merging #2260 into master will decrease coverage by 0.14%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2260      +/-   ##
==========================================
- Coverage   66.84%   66.69%   -0.15%     
==========================================
  Files         208      208              
  Lines       16926    16926              
==========================================
- Hits        11314    11289      -25     
- Misses       4256     4271      +15     
- Partials     1356     1366      +10

Flag	Coverage Δ
#criv1alpha1test	32.53% <ø> (-0.19%)	⬇️
#criv1alpha2test	36.17% <ø> (+0.19%)	⬆️
#integrationtest	39.54% <ø> (+0.04%)	⬆️
#nodee2etest	33.3% <ø> (-0.19%)	⬇️
#unittest	23.75% <ø> (ø)	⬆️

Impacted Files	Coverage Δ
cri/ocicni/cni_manager.go	65% <0%> (-15%)	⬇️
daemon/containerio/cri_log_file.go	84.31% <0%> (-3.93%)	⬇️
daemon/mgr/system.go	76.22% <0%> (-1.64%)	⬇️
daemon/logger/jsonfile/utils.go	71.54% <0%> (-1.63%)	⬇️
daemon/mgr/spec_linux.go	74.47% <0%> (-1.51%)	⬇️
cri/v1alpha2/cri.go	66.46% <0%> (-0.9%)	⬇️
cri/v1alpha1/cri.go	61.52% <0%> (-0.34%)	⬇️
cri/v1alpha2/cri_utils.go	90.33% <0%> (-0.3%)	⬇️
daemon/mgr/container.go	57.39% <0%> (-0.21%)	⬇️
cri/v1alpha2/cri_wrapper.go	62.4% <0%> (ø)	⬆️
... and 1 more

[fuweid]

LGTM

[fuweid]

CI failed by adding one line

/home/travis/gopath/src/github.com/alibaba/pouch/test/cli_inspect_test.go:140:
    c.Assert(output, check.Equals, errCase.expectedOutput)
... obtained string = "" +
...     "\n" +
...     "Run 'pouch --help' for usage.\n" +
...     "Error: Fetch object error: {\"message\":\"container multi-inspect-print-1: not found\"}\n" +
...     "Error: Fetch object error: {\"message\":\"container multi-inspect-print-2: not found\"}\n"
... expected string = "" +
...     "\n" +
...     "Error: Fetch object error: {\"message\":\"container multi-inspect-print-1: not found\"}\n" +
...     "Error: Fetch object error: {\"message\":\"container multi-inspect-print-2: not found\"}\n"