apparmor-tumbler: log what we're going to do before we do it

This typically makes logs from automated tests more useful.

Reviewed-by: Philip Withnall <philip.withnall@collabora.co.uk>
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Differential Revision: https://phabricator.apertis.org/D3479

apparmor/tumbler/test-tumbler

@@ -2,6 +2,7 @@
 # vim: tw=0
 
 set -e
+set -x
 
 TEST_DIR=$(cd $(dirname $0); pwd; cd - &>/dev/null)
 # We want to use the pre-existing session bus.
@@ -12,4 +13,6 @@ exit_status=0
 "${TEST_DIR}"/run-aa-test "${TEST_DIR}"/tumbler.normal.expected "${TEST_DIR}"/tumbler normal || exit_status=$?
 "${TEST_DIR}"/run-aa-test "${TEST_DIR}"/tumbler.malicious.expected "${TEST_DIR}"/tumbler malicious || exit_status=$?
 
+# Output is boring below here
+set +x
 exit "$exit_status"