XenAPI:  Fix final script to include functions

Generally a ubuntu template is supplied - but in the case
where it is not, we need to source functions before sourcing
stackrc (Through xenrc)

Change-Id: I8325cf1c6f83946b7798e6d1bb8278e86831d3c4
diff --git a/tools/xen/scripts/install_ubuntu_template.sh b/tools/xen/scripts/install_ubuntu_template.sh
index d80ed09..d4d6567 100755
--- a/tools/xen/scripts/install_ubuntu_template.sh
+++ b/tools/xen/scripts/install_ubuntu_template.sh
@@ -14,6 +14,9 @@
 # This directory
 BASE_DIR=$(cd $(dirname "$0") && pwd)
 
+# Source the top level functions
+source $BASE_DIR/../../../functions
+
 # For default setings see xenrc
 source $BASE_DIR/../xenrc