change if for optargs

salt/common/tools/sbin/soup

@@ -200,8 +200,7 @@ verify_latest_update_script() {
 while getopts ":b" opt; do
   case ${opt} in
     b ) # process option b
-      re='^[0-9]+$'
-      if [[ $OPTARG =~ $re ]]; then
+      if [[ "$OPTARG" =~ ^[0-9]+$ ]]; then
         BATCHSIZE=$OPTARG
       else
         echo "Batch size must be a number greater than 0"