selinux_build_module_simple.sh: fix quoting

If module_name or module_dir had a space, this script would fail.

Also avoid existence test for the tmp dir and use mkdir -p instead.

files/selinux_build_module_simple.sh

@@ -4,13 +4,13 @@ module_dir="$2"
 
 set -e
 
-cd $module_dir
-test -d tmp || mkdir tmp
+cd "$module_dir"
+mkdir -p tmp
+
+checkmodule -M -m -o "tmp/${module_name}.mod" "${module_name}.te"
 
-checkmodule -M -m -o tmp/${module_name}.mod ${module_name}.te
-package_args="-o ${module_name}.pp -m tmp/${module_name}.mod"
 if [ -s "${module_name}.fc" ]; then
-    package_args="${package_args} --fc ${module_name}.fc"
+    semodule_package -o "${module_name}.pp" -m "tmp/${module_name}.mod" --fc "${module_name}.fc"
+else
+    semodule_package -o "${module_name}.pp" -m "tmp/${module_name}.mod"
 fi
-
-semodule_package ${package_args}