virttest/utils_misc: Fix return code of run_tests()

When the detailed test status was introduced, we did
not update the criteria to determine when a test passed
or failed. Let's fix that problem by checking the
base job test status to boolean mapping and then deciding.

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
Merge pull request #1697 from autotest/fix-utils-misc

virttest/utils_misc: Fix return code of run_tests()