Fix ntp_conf variable

Related-Prod: PRODX-3456
Change-Id: Ib0734f554280b9ef2e0304b1ef628172377ead5e
diff --git a/de/heat-templates/scripts/functions.sh b/de/heat-templates/scripts/functions.sh
index 18db32f..79ce4d5 100644
--- a/de/heat-templates/scripts/functions.sh
+++ b/de/heat-templates/scripts/functions.sh
@@ -545,6 +545,7 @@
 
 function configure_ntp {
     if [[ ${CODENAME} == "bionic" ]] || [[ ${CODENAME} == "focal" ]] || [[ ${CODENAME} == "jammy" ]]; then
+        local ntp_conf="/etc/ntp.conf"
         local ntp_service_name="ntp"
 
         echo "" > ${ntp_conf}
@@ -555,7 +556,7 @@
 EOF
     done
 
-    cat << EOF >> /etc/ntp.conf
+    cat << EOF >> ${ntp_conf}
 # Set general access to this service
 restrict -4 default kod nomodify notrap nopeer noquery
 restrict -6 default kod nomodify notrap nopeer noquery