[mythtv] Ringbuffer: fsync thread may equal corruption

[Daniel Thor Kristjansson]

]It is very weird.  A show can become corrupt within minutes of it starting, or
]not until it is over 2 hours into it, or not at all.  Most of the time, once a
]show is corrupt, it continues to be corrupt until the recording is over.
]Sometimes, however, it will recover after several minutes and be okay until the
]end.

The corruption I can't explain, but I've seen corruption cause problems 
for the rest of the recording before all our brave new patches. ffmpeg 
and the audio decoder can both get into funky states they can't 
extricate themselves from because of one transient glitch.

-- Daniel