Revert "stagefright: add an extra buffer to ANW's BUfferQueue"

Cause errors for playback on YouTube.
Logcat: http://pastebin.com/gRPHJHez

This reverts commit 2bce3e06f60a8d60c81261b0438d0cc6f2bbe7d1.

Change-Id: Id78442831e95b6021ea8b6d3648678db094f4565