Make 1989/fubar/fubar.sh use bash

Fixed for ShellCheck as well.

The if [ .. ] was changed to if [[ .. ]] and this was done in the C code
as well.

1989/fubar/fubar.sh

@@ -1,8 +1,8 @@
-#!/usr/bin/env sh
+#!/usr/bin/env bash
 # to run fubar in the 'proper' way
 
 # parse args
-if [ $# -ne 1 ]; then
+if [[ $# -ne 1 ]]; then
     echo "usage: $0 number" 1>&2
     exit 1
 fi
@@ -15,5 +15,5 @@ r fubar.c
 w ouroboros.c
 EOF
 chmod +x ouroboros.c
-./ouroboros.c $1
+./ouroboros.c "$1"
 #rm -f ouroboros.c x1 x