change if for optargs

salt/common/tools/sbin/soup

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