[autotest] Allow spaces in directory names.

`find | xargs` would choke on directories whose names contained spaces.
`find -print0 | xargx --null` is the way to fix this.

BUG=None
TEST=Ran it

Change-Id: Ib2d04a22196277e9da92ebe1a6d9c1ae2516f894
Reviewed-on: https://gerrit.chromium.org/gerrit/43216
Tested-by: Alex Miller <milleral@chromium.org>
Reviewed-by: Simran Basi <sbasi@chromium.org>
Commit-Queue: Alex Miller <milleral@chromium.org>
diff --git a/site_utils/setup_dev_autotest.sh b/site_utils/setup_dev_autotest.sh
index 67e6da8..2f6fb2b 100755
--- a/site_utils/setup_dev_autotest.sh
+++ b/site_utils/setup_dev_autotest.sh
@@ -196,7 +196,7 @@
 sudo a2enmod python
 # Setup permissions so that Apache web user can read the proper files.
 chmod -R o+r "${AT_DIR}"
-find "${AT_DIR}"/ -type d | xargs chmod o+x
+find "${AT_DIR}"/ -type d -print0 | xargs --null chmod o+x
 chmod o+x "${AT_DIR}"/tko/*.cgi
 # restart server
 sudo /etc/init.d/apache2 restart