SurfaceTexture: dequeueBuffer hack for older EGL blobs

If MISSING_GRALLOC_BUFFERS is defined (i.e., we're already hacking
around the lack of native buffers), allow retrying buffer dequeues
when the operation returns an error.
Based on work by "rapmv78" at xda-developers
(http://forum.xda-developers.com/showpost.php?p=20342919&postcount=1)

Change-Id: I2b672aabc8b2bf7b76d11c9a8e4bd65f0b4a40cf