Replace '\0 bytes' by 'NULL bytes' in Doxygen comments.

Doxygen mistakes the \ for the start of a Doxygen command.

Originally committed as revision 23994 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/chomp_bsf.c

@@ -38,7 +38,7 @@ static int chomp_filter(AVBitStreamFilterContext *bsfc,
 }
 
 /**
- * This filter removes a string of \0 bytes from the end of a packet.
+ * This filter removes a string of NULL bytes from the end of a packet.
  */
 AVBitStreamFilter chomp_bsf = {
     "chomp",