Nits: more punctuation and capitalization

Commited in SoC by Vitor Sessak on 2008-02-09 20:02:29

Originally committed as revision 12043 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavfilter/avfilter.c

 /*
- * Filter layer
+ * filter layer
  * copyright (c) 2007 Bobby Bingham
  *
  * This file is part of FFmpeg.