[MPlayer-dev-eng] vo control vaarg cleanup

[Ivan Kalvachev]

Remove the variable arguments from the libvo control() functions.

No module uses the vaarg anymore. Also it is cleaner to provide
pointer to specific structure than specify arguments via vaarg.

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I intend to use the above as commit message. If you have better one, post it.

The patch is straight forward,
In vosub_vidix.c I change commented code (I don't consider this
cosmetics) and I remove a comment about vaarg not been passed though.
If you insist I can commit them separately.

I'll commit it in a day or two.

Best Regards
  Ivan Kalvachev