scripts/oe-selftest: Remove extra coverage data added to unittests
Coverage data tracking initiates too early, causing coverage data from the
oe-selftest environment setting to be added to each run. Even when no tests are run
oe-selftest reports around 24% of coverage due to this extra data.
Change the custom resultclass used by the TextTestRunner to one generated from the
command arguments. The generated class processes coverage when needed, running
coverage setup just before the first testcase is run and reporting after the last
one finished.
[Yocto #8846]
Signed-off-by: Humberto Ibarra <humberto.ibarra.lopez@intel.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
