Fix a bug when comparing two values.

Bug fixed by: Masa
diff --git a/scripts/demo-scale-out-sw.sh b/scripts/demo-scale-out-sw.sh
index 9e988bf..762a00e 100755
--- a/scripts/demo-scale-out-sw.sh
+++ b/scripts/demo-scale-out-sw.sh
@@ -13,7 +13,7 @@
       ssh -i ~/.ssh/onlabkey.pem  ${basename}${i} 'cd ONOS;./start-onos.sh status' &
     done | grep "instance" | awk '{s+=$1}END{print s}'`
 
-    if [ x$up == 4 ]; then
+    if [ x$up == "x4" ]; then
       break;
     fi 
     sleep 1