cmd/stress: use an ellipsis when truncating output

While investigating golang/go#36664, the entire output of a failure
could get pretty long - past fifty lines of content. I was getting
confused as to why the output was being cut off.

I had to discard a number of theories (the test being buggy, my expected
output being wrong, etc) before I realised that something was truncating
the output for the sake of the reader.

Since that's what stress is doing, make it add an ellipsis character
too, to further hint to the user that the output is being truncated for
readability. Separate it with a newline to make it easier to notice.

Change-Id: Ie052c13bb48d6fd842d6054848161266d9ea17e6
Reviewed-on: https://go-review.googlesource.com/c/tools/+/215597
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>

0 files changed, 0 insertions, 0 deletions