Fix make lint warning

[piyush-garg]

This will fix the warnings issued by
make lint command

Fixes #422

Submitter Checklist

These are the criteria that every PR should meet, please check them off as you
review them:

• Includes tests (if functionality changed/added)
• Includes docs (if user facing)
• Regenerate the manpages and docs with make docs and make man if needed.
• Run the code checkers with make check
• Commit messages follow commit message best practices

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[tekton-robot]

The following is the coverage report on pkg/.
Say /test pull-tekton-cli-go-coverage to re-run this coverage report

File	Old Coverage	New Coverage	Delta
pkg/cmd/pipelineresource/create.go	57.7%	75.9%	18.2

[piyush-garg]

/test pull-tekton-cli-go-coverage

[piyush-garg]

/test pull-tekton-cli-go-coverage

[vdemeester]

/lgtm

[tekton-robot]

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