xfstests: add local.config example

I think it'd be useful to have a local.config template in the
git repo, to avoid having to re-read the README each time
to remember the required environment variable names.

Thoughts?  Am I just lazy?  :)

Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Rich Johnston <rjohnston@sgi.com>
Signed-off-by: Rich Johnston <rjohnston@sgi.com>

local.config.example

@@ -0,0 +1,10 @@
+# Ideally define at least these 4 to match your environment
+# The first 2 are required.
+# See README for other variables which can be set.
+#
+# Note: SCRATCH_DEV >will< get overwritten!
+
+export TEST_DEV=/dev/sdX1
+export TEST_DIR=/mnt/test
+export SCRATCH_DEV=/dev/sdX2
+export SCRATCH_MNT=/mnt/scratch