Remove stray non-existent -o option from an example.

patch by Michel Bardiaux < mbardiaux -- at -- mediaxim -- dot -- be >

Originally committed as revision 4562 to svn://svn.ffmpeg.org/ffmpeg/trunk

doc/ffmpeg-doc.texi

@@ -75,7 +75,7 @@ horizontal resolution.
 * You can output to a raw YUV420P file:
 
 @example
-ffmpeg -i mydivx.avi -o hugefile.yuv
+ffmpeg -i mydivx.avi hugefile.yuv
 @end example
 
 * You can set several input files and output files: