integration: chown ceilometer directory properly

The STACK_USER needs to be able to write the ceilo dir.

Change-Id: Icef809d14bb42c7e02a98b16bab184ef3fc4613c
diff --git a/ceilometer/tests/integration/hooks/post_test_hook.sh b/ceilometer/tests/integration/hooks/post_test_hook.sh
index 65c9ed7..00851e5 100755
--- a/ceilometer/tests/integration/hooks/post_test_hook.sh
+++ b/ceilometer/tests/integration/hooks/post_test_hook.sh
@@ -32,7 +32,7 @@
 if [ -d $BASE/new/devstack ]; then
     export CEILOMETER_DIR="$BASE/new/ceilometer"
     STACK_USER=stack
-    sudo chown -R jenkins:stack $CEILOMETER_DIR
+    sudo chown -R $STACK_USER:stack $CEILOMETER_DIR
     source $BASE/new/devstack/openrc admin admin
     # Go to the ceilometer dir
     cd $CEILOMETER_DIR