misc: log 'ok' from 'go run' tests on success

Otherwise, these tests produce no output, which can make the overall
output of all.bash a bit tricky to decipher.

Updates #30316
Updates #29062

Change-Id: I33b9e070fd28b9f21ece128e9e603a982c08b7cc
Reviewed-on: https://go-review.googlesource.com/c/go/+/208483


Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Jay Conrod <jayconrod@google.com>