Fix build emails when no errors and no warnings
Fix build emails when no errors and no warnings

Adding support for multiple compilers broke the build reports in
sevaral places, this is a simple fix to avoid exceptions when there
are no errors and no warnings in any of the builds.

This code should really need to be reviewed and rewritten with a
simpler implementation.

Fixes: 472c74146a6b ("Fix build emails blaiming wrong compiler")
Signed-off-by: Guillaume Tucker <e7e20b7c30f19d4ca6b81319ef81bf200369d137@collabora.com>

kernelci/kernelci-backend,kernelci/kernelci-backend