vm: use $DISTRO_NAME instead of lsb_release

Use the distribution string already available as $DISTRO_NAME.

Change-Id: I4aa3b19d66cc4bed39e9778f0ed21e86743afe41

elements/vm/finalise.d/50-remove-bogus-udev-links

@@ -6,7 +6,7 @@ fi
 set -eu
 set -o pipefail
 
-if [ "openSUSE project" = "$(lsb_release -is)" ]; then
+if [ $DISTRO_NAME = 'opensuse' ] ; then
     # workaround for https://bugzilla.novell.com/show_bug.cgi?id=859493
     rm -f /dev/mapper/loop*_part1
 fi