Fix overriding GenerateName on taskrun

[16yuki0702]

Changes

This fixes #666

when user specified last flag, script always override GenerateName.
So using GenerateName if last TaskRun has a GenerateName,
If not, setting a GenerateName based on last TaskRun Name.

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Release Notes

release-note

[tekton-robot]

Hi @16yuki0702. Thanks for your PR.

I'm waiting for a tektoncd member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[chmouel]

/ok-to-test

[chmouel]

@16yuki0702 would you like to add your login to this list? : https://github.com/tektoncd/community/blob/master/org/org.yaml i think that's what needed so you don't need a ok-to-test for all your PR all the time

[16yuki0702]

@chmouel

would you like to add your login to this list? : https://github.com/tektoncd/community/blob/master/org/org.yaml i think that's what needed so you don't need a ok-to-test for all your PR all the time

Yes, I'd like to add to the lists thanks 😄

[chmouel]

/lgtm

[tekton-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: piyush-garg

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[piyush-garg]

/lgtm