[CMake] [Cdash] Show results from the bullseye coverage in CDash

[David Cole]

Sometimes an unfortunate network interruption (even a very brief one,
at just the wrong time...) can cause my bullseye dashboards to report
"0%" coverage. I use the license manager for Bullseye, so the build
machine needs network access to the license manager machine when
turning coverage on and off with the "cov01" Bullseye tool. If there is
no network access at "call cov01 -1" time, then trying to turn on
coverage measurement cannot succeed, and the result is a coverage build
without any coverage data: 0%.

You can probably tell if this is happening to you or not by paying
attention to the return value of cov01. I suspect it returns an error
code in this condition, but my scripts just ignore it and continue with
the build anyhow.

HTH,
David C.