strtok stores its values in thread local storage.
So it can not guarantee works well when multithread environment.
AudioFlinger has multithread.
so strtok_r is more safe.

Change-Id: I6d77ef9cc49a4478dd856dcdca14e4920ce955c6
Merge "strtok stores its values in thread local storage. So it can not guarantee works well when multithread environment. AudioFlinger has multithread. so strtok_r is more safe." into jb43