kunit: Reset test status on each param iteration

If we skip one parametrized test case then test status remains
SKIP for all subsequent test params leading to wrong reports:

$ ./tools/testing/kunit/kunit.py run \
	--kunitconfig ./lib/kunit/.kunitconfig *.example_params*
	--raw_output \

[ ] Starting KUnit Kernel (1/1)...
KTAP version 1
1..1
    # example: initializing suite
    KTAP version 1
    # Subtest: example
    # module: kunit_example_test
    1..1
        KTAP version 1
        # Subtest: example_params_test
    # example_params_test: initializing
    # example_params_test: cleaning up
        ok 1 example value 3 # SKIP unsupported param value 3
    # example_params_test: initializing
    # example_params_test: cleaning up
        ok 2 example value 2 # SKIP unsupported param value 3
    # example_params_test: initializing
    # example_params_test: cleaning up
        ok 3 example value 1 # SKIP unsupported param value 3
    # example_params_test: initializing
    # example_params_test: cleaning up
        ok 4 example value 0 # SKIP unsupported param value 0
    # example_params_test: pass:0 fail:0 skip:4 total:4
    ok 1 example_params_test # SKIP unsupported param value 0
    # example: exiting suite
ok 1 example # SKIP

Reset test status and status comment after each param iteration
to avoid using stale results.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: David Gow <davidgow@google.com>
Cc: Rae Moar <rmoar@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>