Merge the two for loops that set up the node lists for
temporaries into one for loop.

Passes toolstash -cmp

Change-Id: Ibc739115f38c8869b0dcfbf9819fdc2fc96962e0
Reviewed-on: https://go-review.googlesource.com/c/141819Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>