This fixes two instances where loop variables were being incorrectly
used:
- using a loop variable in a closure passed to `ginkgo.It()` is
incorrect, as the capture happens by reference and only the last test
case will be executed (multiple times).
- a similar issue happens in the context of a goroutine; specifically,
we need to create a copy of the `runDurationFunc` before calling it in
a goroutine as done by the controller's `Run` function.
With regards to the second issue, I believe it never came to the
surface because, in production code, only one `runDurationFunc` is
passed; tests don't exercise the multiple funcs path either.
Issues were automatically found with the `loopvarcapture` linter.
Signed-off-by: Renato Costa <renato@cockroachlabs.com>
162777aab2