exit soup if batch size invalid

salt/common/tools/sbin/soup

@@ -204,6 +204,7 @@ while getopts ":b" opt; do
         BATCHSIZE=$OPTARG
       else
         echo "Batch size must be a number greater than 0"
+        exit 1
       fi
       ;;
     \? ) echo "Usage: cmd [-b]"