Fix "Variable '${TEST_NAME}' not found" error in FFDC
Fix "Variable '${TEST_NAME}' not found" error in FFDC

When FFDC is run from suite setup or teardown, variables like TEST_NAME
are not defined.  Set them to None in such cases to allow FFDC
collection to continue.

Also made some miscellaneous style fixes.

Change-Id: I3ec9e26d869ce41fa5d752af0be74cedbee437cf
Signed-off-by: Michael Walsh <10404802c7de463f402c4a18638106ca1b12ef61@us.ibm.com>

openbmc/openbmc-test-automation,openbmc/openbmc-test-automation