Code review comment for lp:~rogpeppe/tomb/update-api

A couple of trivials, and should be ready to submit.

https://codereview.appspot.com/5755055/diff/6003/tomb.go
File tomb.go (right):

https://codereview.appspot.com/5755055/diff/6003/tomb.go#newcode106
tomb.go:106: t.init()
init isn't needed here.

https://codereview.appspot.com/5755055/diff/6003/tomb_test.go
File tomb_test.go (right):

https://codereview.appspot.com/5755055/diff/6003/tomb_test.go#newcode19
tomb_test.go:19: // the Kill reason flags the goroutine as dying
s/Kill/nil/

https://codereview.appspot.com/5755055/diff/6003/tomb_test.go#newcode24
tomb_test.go:24: // a non-Kill reason now will override Kill
s/Kill/nil/g

https://codereview.appspot.com/5755055/