chore(wasm): return early on error in init_worker (#11248)

This makes wasm's init_worker error-handling conformant with the rest of
the logic in Kong.init_worker().

kong/init.lua

@@ -870,6 +870,7 @@ function Kong.init_worker()
   if not ok then
     err = "wasm nginx worker initialization failed: " .. tostring(err)
     stash_init_worker_error(err)
+    return
   end
 end