Refactor pass/fail/skip code in PM-QA

Focus on returning the results of each test script rather
than the results of each subtest. This will help to keep the
number of PM-QA test results consistent across multiple boards
regardless of number of frequencies, cores, etc.

Examples before the refactoring:

https://validation.linaro.org/dashboard/streams
/anonymous/lisatn/bundles/331786fb33a49b060adccf51bb509d5f286422e7/

Examples after the refactoring:

https://validation.linaro.org/dashboard/streams/anonymous
/lisatn/bundles/076a3f890e58727f01a23e30d6eb438172b69c7d/

Once this patch is accepted and merged, then there will be a
follow up patch to update the pwrmgmt test definition, so LAVA
can record PM-QA results accurately.

bug : https://bugs.linaro.org/show_bug.cgi?id=155

Acked-by: Sanjay Singh Rawat<sanjay.rawat@linaro.org>
Signed-off-by: Lisa Nguyen <lisa.nguyen@linaro.org>
diff --git a/thermal/thermal_06.sh b/thermal/thermal_06.sh
index 92c987a..d8877f0 100755
--- a/thermal/thermal_06.sh
+++ b/thermal/thermal_06.sh
@@ -30,7 +30,7 @@
 
 if [ "$thermal_try_max" -eq 0 ]; then
     log_skip "test of trip points being crossed"
-    exit 0
+    return 0
 fi
 
 TEST_LOOP=100