Minor fixes for bashate trunk

We don't have a new bashate release yet, but this fixes some minor
issues when used with bashate trunk.

The only two things triggered are stricter checking of assignment in
local declartions (catches quotes) and one instance of evaluating
arithmetic result in tools/xen/functions.

Therefore, hopefully, this change has no effect!

Change-Id: I3fd5d55236e90c2f2c25243af87adaf0c1b763e2
diff --git a/functions-common b/functions-common
index ff9bc0f..f84301f 100644
--- a/functions-common
+++ b/functions-common
@@ -1211,7 +1211,7 @@
     local files_to_parse=""
     local package_dir=""
     for plugin in ${DEVSTACK_PLUGINS//,/ }; do
-        local package_dir="$(_get_package_dir ${GITDIR[$plugin]}/devstack/files)"
+        package_dir="$(_get_package_dir ${GITDIR[$plugin]}/devstack/files)"
         files_to_parse+=" $package_dir/$plugin"
     done
     echo "$(_parse_package_files $files_to_parse)"