Updating scripts for release

Change-Id: I5c3cfb60d10de03e3f60643bb6d655869ccc8562
diff --git a/tools/build/onos-release b/tools/build/onos-release
index 3bc4f4d..48676cc 100755
--- a/tools/build/onos-release
+++ b/tools/build/onos-release
@@ -8,7 +8,7 @@
 
 set -e
 
-export NEW_VERSION=$1
+export NEW_VERSION=${1:-$ONOS_VERSION}
 [ -z "$NEW_VERSION" ] && echo "New ONOS version not specified" && exit 1
 
 export NEW_VERSION_SHORT=${NEW_VERSION%-SNAPSHOT}