The test scripts create a bunch of temporary files to keep track of
internal state. Some are made in /tmp with individual mktemp calls, some
go in the passt source directory, and some go in $LOGDIR. This can
sometimes make it messy to clean up after failed test runs.
Start cleaning this up by creating a single "state" directory ($STATEBASE)
in /tmp for all the state or temporary files used by a single test run.
Clean it up automatically in cleanup() - except when DEBUG==1, because
those files can be useful for debugging test script failures.
We create subdirectories under $STATEBASE for each setup function, exposed
as $STATESETUP. We also create subdirectories for each test script and
expose those to the scripts as __STATEDIR__.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
8cb7d5b461